Online Etymology Dictionary

teeter (v.): 1843, "to seesaw," alteration of Middle English titter "move unsteadily," probably from a Scandinavian source akin to Old Norse titra "to shake, shiver, totter, tremble," from Proto-Germanic *ti-tra- (source also of German zittern "to tremble"). Meaning "move unsteadily, be on the edge of imbalance" is from 1844. Noun teeter-totter "see-saw" is attested from 1905 (earlier simply teeter, 1855, and titter-totter in same sense is from 1520s). Totter (n.) "board swing" is recorded from late 14c.; see totter (v.).
temperance (n.): mid-14c., "self-restraint, moderation," from Anglo-French temperaunce (mid-13c.), from Latin temperantia "moderation, sobriety, discretion, self-control," from temperans, present participle of temperare "to moderate" (see temper (v.)). Latin temperantia was used by Cicero to translate Greek sophrosyne "moderation." In English, temperance was used to render Latin continentia or abstinentia, specifically in reference to drinking alcohol and eating; hence by early 1800s it had come to mean "abstinence from alcoholic drink."
tenuous (adj.): 1590s, "thin, unsubstantial," irregularly formed from Latin tenuis "thin, drawn out, meager, slim, slender," figuratively "trifling, insignificant, poor, low in rank," from PIE root *ten- "to stretch" (source also of Sanskrit tanuh "thin," literally "stretched out;" see tenet) + -ous. The correct form with respect to the Latin is tenuious. The figurative sense of "having slight importance, not substantial" is found from 1817 in English. Related: Tenuously; tenuousness.
vibrate (v.): 1610s (intransitive) "move to and fro;" 1660s, "swing to and fro;" from Latin vibratus, past participle of vibrare "set in tremulous motion, move quickly to and fro, quiver, tremble, shake," from PIE *wib-ro-, from root *weip- "to turn, vacillate, tremble ecstatically, move quickly to and fro" (source also of Lithuanian wyburiu "to wag" (the tail), Danish vippe, Dutch wippen "to swing," Old English wipan "to wipe"). Transitive sense "cause to vibrate" is from c. 1700. Related: Vibrated; vibrating.
opening (n.): Old English openung "act of opening" (a door, mouth, etc.), "disclosure, manifestation," verbal noun from present participle of open (v.). Meaning "vacant space, hole, aperture, doorway" is attested from c. 1200. Meaning "act of opening (a place, to the public)" is from late 14c. Sense of "action of beginning (something)" is from 1712; meaning "first performance of a play" is 1855; "start of an art exhibit" is from 1905. Sense of "opportunity, chance" is from 1793.
operate (v.): c. 1600, "to be in effect," back-formation from operation, or else from Latin operatus, past participle of operari "to work, labor, toil, take pains" (in Late Latin "to have effect, be active, cause"). Surgical sense is first attested 1799. Meaning "to work machinery" is from 1864 in American English. Related: Operated; operating. Operating system in the computer sense is from 1961.
oracle (n.): late 14c., "a message from a god, expressed by divine inspiration," from Old French oracle "temple, house of prayer; oracle" (12c.) and directly from Latin oraculum "divine announcement, oracle; place where oracles are given," from orare "pray, plead" (see orator), with material instrumental suffix -culo-. In antiquity, "the agency or medium of a god," also "the place where such divine utterances were given." This sense is attested in English from c. 1400.
oratorio (n.): "long musical composition, usually with a text based on Scripture," 1727 (in English from 1640s in native form oratory), from Italian oratorio (late 16c.), from Church Latin oratorium (see oratory (n.2)), in reference to musical services in the church of the Oratory of St. Philip Neri in Rome, where old mystery plays were adapted to religious services.
orc (n.): "ogre, devouring monster," Old English orcþyrs, orcneas (plural), perhaps from a Romanic source akin to ogre, and ultimately from Latin Orcus "Hell," a word of unknown origin. Revived by J.R.R. Tolkien (1892-1973) as the name of a brutal race in Middle Earth.
But Orcs and Trolls spoke as they would, without love of words or things; and their language was actually more degraded and filthy than I have shown it. ["Return of the King," 1955]
Ordovician (adj.): geological period following the Cambrian and preceding the Silurian, 1879, coined by English geologist Charles Lapworth (1842-1920) from Latin Ordovices, name of an ancient British tribe in North Wales. The period so called because rocks from it first were studied extensively in the region around Bala in North Wales. The tribe's name is Celtic, literally "those who fight with hammers," from Celtic base *ordo "hammer" + PIE *wik- "to fight, conquer" (see victor).
oregano (n.): 1771, from Spanish or American Spanish oregano, from Latin origanus, origanum, from Greek oreiganon, from oros "mountain" (see oread) + ganos "brightness, ornament." The older form of the word in English was the Latin-derived origanum (mid-13c.), also origan (early 15c.). In Europe, the dried leaves of wild marjoram; in America, a different, and more pungent, shrub.
manage (v.): 1560s, probably from Italian maneggiare "to handle," especially "to control a horse," ultimately from Latin noun manus "hand" (see manual (adj.)). Influenced by French manège "horsemanship" (earliest English sense was of handling horses), which also was from Italian. Extended to other objects or business from 1570s. Slang sense of "get by" first recorded 1650s. Related: Managed; managing. Managed economy was used by 1933.
mandrake (n.): narcotic plant, early 14c., mondrake, from Medieval Latin mandragora, from Latin mandragoras, from Greek mandragoras, probably from a non-Indo-European word. The word was in late Old English in its Latin form; folk etymology associated the second element with dragoun and substituted native drake in its place. The forked root is thought to resemble a human body and is said to shriek when pulled from the ground.
manna (n.): Old English borrowing from Late Latin manna, from Greek manna, from Hebrew man, probably literally "substance exuded by the tamarisk tree," but used in Greek and Latin specifically with reference to the substance miraculously supplied to the Children of Israel during their wandering in the Wilderness (Ex. xvi:15). Meaning "spiritual nourishment" is attested from late 14c. Generalized sense of "something provided unexpectedly" is from 1590s.
manslaughter (n.): mid-14c., " act, crime, or sin of killing another human being," in battle or not, from man (n.) + slaughter (n.). Replaced Old English mannslæht (Anglian), mannslieht (West Saxon), from slæht, slieht "act of killing" (see slay). Etymologically identical with homicide, but in legal use usually distinguished from murder and restricted to "simple homicide."
manta (n.): very large ray (also called devilfish), 1760, from Spanish manta "blanket" (which is attested in English from 1748 in this sense, specifically in reference to a type of wrap or cloak worn by Spaniards), from Late Latin mantum "cloak," back-formation from Latin mantellum "cloak" (see mantle (n.)). The ray so called "for being broad and long like a quilt" [Jorge Juan and Antonio de Ulloa, "A Voyage to South America"].
mantra (n.): 1808, "that part of the Vedas which contains hymns," from Sanskrit mantra-s "sacred message or text, charm, spell, counsel," literally "instrument of thought," related to manyate "thinks," from PIE root *men- "to think" (see mind (n.)). Sense of "special word used for meditation" is first recorded in English 1956.
manual (adj.): c. 1400, from Latin manualis "of or belonging to the hand; that can be thrown by hand," from manus "hand, strength, power over; armed force; handwriting," from PIE *man- (2) "hand" (source also of Old Norse mund "hand," Old English mund "hand, protection, guardian," German Vormund "guardian," Greek mane "hand").
many (adj.): Old English monig, manig "many, many a, much," from Proto-Germanic *managaz (source also of Old Saxon manag, Swedish mången, Old Frisian manich, Dutch menig, Old High German manag, German manch, Gothic manags), from PIE *menegh- "copious" (source also of Old Church Slavonic munogu "much, many," Old Irish menicc, Welsh mynych "frequent," Old Irish magham "gift"). Pronunciation altered by influence of any (see manifold).
nepenthe (n.): 1570s, nepenthes, from Greek nepenthes, from ne- "no, not" (see un-) + penthos "pain, grief," from PIE *kwent(h)- "to suffer" (see pathos). A drug of Egypt mentioned in the "Odyssey" as capable of banishing grief or trouble from the mind. The -s is a proper part of the word, but likely was mistaken in English as a plural affix and dropped.
-ness: word-forming element denoting action, quality, or state, attached to an adjective or past participle to form an abstract noun, from Old English -nes(s), from Proto-Germanic *in-assu- (cognates: Old Saxon -nissi, Middle Dutch -nisse, Dutch -nis, Old High German -nissa, German -nis, Gothic -inassus), from *-in-, noun stem, + *-assu-, abstract noun suffix, probably from the same root as Latin -tudo (see -tude).
net (n.): Old English net "netting, network, spider web, mesh used for capturing," also figuratively, "moral or mental snare or trap," from Proto-Germanic *natjan (source also of Old Saxon net, Old Norse, Dutch net, Swedish nät, Old High German nezzi, German Netz, Gothic nati "net"), originally "something knotted," from PIE *ned- "to twist, knot" (source also of Sanskrit nahyati "binds, ties," Latin nodus "knot," Old Irish nascim "I bind, oblige").
nether (adj.): Old English niþera, neoþera "down, downwards, below, beneath," from Proto-Germanic *nitheraz (source also of Old Saxon nithar, Old Norse niðr, Old Frisian nither, Dutch neder, German nieder), from comparative of PIE *ni- "down, below" (source also of Sanskrit ni "down," nitaram "downward," Greek neiothen "from below," Old Church Slavonic nizŭ "low, down"). Has been replaced in most senses by lower (adj.).
nettle (n.): stinging plant, Old English netele, from Proto-Germanic *natilon (source also of Old Saxon netila, Middle Dutch netele, Dutch netel, German Nessel, M.Da. nædlæ "nettle"), diminutive of *naton, perhaps from PIE root *ned- "to twist, knot" (see net (n.)). "[N]ettles or plants of closely related genera such as hemp were used as a source of fiber" [Watkins].
next (adj.): Old English niehsta, nyhsta (West Saxon), nesta (Anglian) "nearest, closest," superlative of neah (West Saxon), neh (Anglian) "nigh;" from Proto-Germanic *nekh- "near" + superlative suffix *-istaz. Cognate with Old Norse næstr, Dutch naast "next," Old High German nahisto "neighbor," German nächst "next." Adverbial and prepositional use from c. 1200. Phrase the next person "a typical person" is from 1857.
nightjar (n.): nocturnal bird, goatsucker, 1620s, from night + jar (v.). So called for the "jarring" sounds made by the male when the female is brooding, which have been described as a "churring trill that seems to change direction as it rises and falls." An Old English word for it was nihthræfn "night raven."
recumbent (adj.): 1705, from Latin recumbentem (nominative recumbens), present participle of recumbere "recline, lie down, lie down again;" of things, "to fall, sink down, settle down," from re- "back" (see re-) + -cumbere "to lie down" (see succumb). Related: Recumbency (1640s). A verb, recumb, has been attempted in English occasionally since 1670s.
redemption (n.): mid-14c., "deliverance from sin," from Old French redemcion (12c.) and directly from Latin redemptionem (nominative redemptio) "a buying back, releasing, ransoming" (also "bribery"), noun of action from past participle stem of redimere "to redeem, buy back," from red- "back" (see re-) + emere "to take, buy, gain, procure" (see exempt). The -d- is from the Old Latin habit of using red- as the form of re- before vowels. In the Mercian hymns, Latin redemptionem is glossed by Old English alesnisse.
redoubt (n.): also redout, "small, enclosed military work," c. 1600, from French redoute (17c.), from Italian ridotto, earlier ridotta, "place of retreat," from Medieval Latin reductus "place of refuge, retreat," noun use of past participle of reducere "to lead or bring back" (see reduce). The -b- was added by influence of unrelated English redoubt (v.) "to dread, fear" (see redoubtable). As an adjective, Latin reductus meant "withdrawn, retired; remote, distant."
reek (n.): Old English rec (Anglian), riec (West Saxon), "smoke from burning material," probably from a Scandinavian source such as Old Norse reykr, Danish rǿg, Swedish rök "smoke, steam," from Proto-Germanic *raukiz (source also of Old Frisian rek, Middle Dutch rooc, Old High German rouh, German Rauch "smoke, steam"), from PIE *reug- "to vomit, belch;" also "smoke, cloud." Sense of "stench" is attested 1650s, via the notion of "that which rises" (compare reek (v.)).
reel (n.1): "frame turning on an axis," especially one on which thread is wound, late Old English hreol "reel for winding thread," from Proto-Germanic *hrehulaz; probably related to hrægel "garment," and Old Norse hræll "spindle," from PIE *krek- "to weave, beat" (source also of Greek krokus "nap of cloth").

Specifically of the fishing rod attachment from 1726; of a film projector apparatus from 1896. Reel-to-reel type of tape deck is attested from 1958.
taw (v.): "to prepare" (leather), from Old English tawian "prepare, make ready, make; cultivate," also "harass, insult, outrage" to do, make," from Proto-Germanic *tawjan (source also of Old Frisian tawa, Old Saxon toian, Middle Dutch tauwen, Dutch touwen, Old High German zouwen "to prepare," Old High German zawen "to succeed," Gothic taujan "to make, prepare"), from Proto-Germanic root *taw- "to make, manufacture" (compare tool (n.)).
teal (n.): "small freshwater duck," early 14c., of uncertain origin, probably from an unrecorded Old English word cognate with Middle Dutch teling "teal," Middle Low German telink, from West Germanic *taili. As the name of a shade of dark greenish-blue resembling the color patterns on the fowl's head and wings, it is attested from 1923 in clothing advertisements.
tear (n.1): "fluid drop from the eye," Old English tear "tear, drop, nectar, what is distilled in drops," from earlier teahor, tæhher, from Proto-Germanic *tahr-, *tagr- (source also of Old Norse, Old Frisian tar, Old High German zahar, German Zähre, Gothic tagr "tear"), from PIE *dakru- (source also of Latin lacrima, Old Latin dacrima, Irish der, Welsh deigr, Greek dakryma). To be in tears "weeping" is from 1550s. Tear gas first recorded 1917.
parch (v.): late 14c., "to roast or dry" (peas, beans, corn, etc.), of uncertain origin. Klein and OED reject derivations from Old North French perchier (Old French percer) "to pierce" and Latin persiccare "to dry thoroughly." Barnhart suggests possibly from Middle English perchen, variant of perishen "to perish" (see perish). Klein "tentatively" suggests a back-formation from parchment. Surname Parchecorn is attested from mid-14c. Meaning "to dry with excessive heat" is mid-15c. Related: Parched; parching.
parquet (n.): 1816, "patterned wooden flooring," from French parquet "wooden flooring; enclosed portion of a park," from Old French parchet (14c.) "small compartment, part of a park or theater," diminutive of parc (see park (n.)).

Meaning "part of a theater auditorium at the front of the ground floor" is first recorded 1848. The noun use in English has been influenced by the verb (attested from 1640s, from French parqueter. Related: Parquetry
partner (n.): c. 1300, altered from parcener (late 13c.), from Old French parçonier "partner, associate; joint owner, joint heir," from parçon "partition, division. portion, share, lot," from Latin partitionem (nominative partitio) "a sharing, partition, division, distribution" (see partition (n.)). Form in English influenced by part (n.). The word also may represent Old French part tenour "part holder."
partridge (n.): late 12c., from Old French pertis, alteration of perdis (perhaps influenced by fem. suffix -tris), from Latin perdicem (nominative perdix) "plover, lapwing," from Greek perdix, the Greek partridge, probably related to perdesthai "to break wind," in reference to the whirring noise of the bird's wings, from PIE imitative base *perd- "to break wind" (source also of Sanskrit pardate "breaks wind," Lithuanian perdzu, Russian perdet, Old High German ferzan, Old Norse freta, Middle English farten).
paschal (adj.): early 15c., "of or pertaining to Easter," from Old French paschal (12c.) and directly from Late Latin paschalis, from pascha "Passover, Easter," from Greek pascha "Passover," from Aramaic pasha "pass over," corresponding to Hebrew pesah, from pasah "he passed over." (see Passover). Pasche was an early Middle English term for "Easter" (see Easter).
pastrami (n.): 1940, from Yiddish pastrame, from Rumanian pastrama, probably from Turkish pastrima, variant of basdirma "dried meat," from root *bas- "to press." Another possible origin of the Rumanian word [Barnhart] is Modern Greek pastono "I salt," from classical Greek pastos "sprinkled with salt, salted." Spelling in English with -mi probably from influence of salami.
pastry (n.): mid-15c., "food made with paste," not originally limited to sweets, from Middle English paste (see paste (n.)) + -ry. Probably influenced by Old French pastaierie "pastry" (Modern French pâtisserie), from pastoier "pastry cook," from paste (see paste (n.)); also borrowed from Medieval Latin pasteria "pastry," from Latin pasta. Specific sense of "small confection made of pastry" is from 1906. Pastry-cook attested from 1712.
rear (v.1): Old English ræran "to raise, build up, create, set on end; arouse, excite, stir up," from Proto-Germanic *raizijanau "to raise," causative of *risanan "to rise" (see rise (v.)). The second -r- is by rhotacism. Meaning "bring into being, bring up" (as a child) is recorded from early 15c.; that of "raise up on the hind legs" is first recorded late 14c. Related: Reared; rearing.
beach (n.): 1530s, "loose, water-worn pebbles of the seashore," probably from Old English bæce, bece "stream," from Proto-Germanic *bakiz. Extended to loose, pebbly shores (1590s), and in dialect around Sussex and Kent beach still has the meaning "pebbles worn by the waves." French grève shows the same evolution. Beach ball first recorded 1940; beach bum first recorded 1950.
beaker (n.): "open large-mouthed vessel," mid-14c., from Old Norse bikarr or Middle Dutch beker "goblet," probably (with Old Saxon bikeri, Old High German behhari, German Becher) from Medieval Latin bicarium, which itself is probably a diminutive of Greek bikos "earthenware jug, wine jar" (said to be an oriental word, perhaps a borrowing from Syrian buqa "a two-handed vase or jug"). Form assimilated in English to beak.
Bedouin (n.): c. 1400, from Old French bedüin (Modern French bédouin), from colloquial Arabic badawin "desert-dwellers," plural of badawi, from badw "desert, camp." The Arabic plural suffix was mistaken for part of the word. A word from the Crusades, it probably was lost in English and then reborrowed from French c. 1600. As an adjective from 1844.
beech (n.): Old English bece "beech," from Proto-Germanic *bokjon (source also of Old Norse bok, Dutch beuk, Flemish boek, Old High German buohha, German Buche, Middle Dutch boeke "beech"), from PIE root *bhagos "beech tree" (cognate with Greek phegos "oak," Latin fagus "beech;" see fagus).

Formerly with adjectival form beechen. Also see book (n.).
before (adv., prep.): Old English beforan "before, in front of, in the presence of, in former times," from Proto-Germanic *bi- "by" + *forana "from the front," adverbial derivative of *fora (see fore (adv.)). Compare Old Frisian bifara, Old Saxon biforan, Old High German bifora, German bevor. Contrasting before and after in illustrations is from Hogarth (1768). Before the mast in old sailing ships denoting "common sailor," is from the place of their berths, in front of the fore-mast.
behave (v.): early 15c., from be- intensive prefix + have in sense of "to have or bear (oneself) in a particular way, comport" (compare German sich behaben, French se porter). Cognate Old English compound behabban meant "to contain," and alternatively the modern sense of behave might have evolved from behabban via a notion of "self-restraint." Related: Behaved; behaving.
behoove (v.): Old English behofian "to have need of, have use for," verbal form of the ancient compound word represented by behoof.
Historically, it rimes with move, prove, but being now mainly a literary word, it is generally made to rime with rove, grove, by those who know it only in books. [OED]
belay (v.): "to secure or fasten," from Old English bilecgan, which, among other senses, meant "to lay a thing about" (with other objects), from be- + lecgan "to lay" (see lay (v.)). The only surviving sense is the nautical one of "coil a running rope round a cleat or pin to secure it" (also transferred to mountain-climbing), first attested 1540s; but this is possibly a cognate word, from Dutch beleggen.