Online Etymology Dictionary

epsilon (n.): from Greek, literally e psilon "bare -e-, -e- and nothing else," so called by late grammarians in contradistinction to the diphthong -ai-, which had come to have the same sound. Greek psilon "smooth, simple" is of uncertain origin (Watkins suggests PIE root *bhes- (1) "to rub").
ingrate (n.): "ungrateful person," 1670s, from earlier adjective meaning "unfriendly," also "ungrateful, unthankful" (14c.), from Latin ingratus "unpleasant, disagreeable," also "ungrateful, unthankful," and "thankless, unprofitable," from in- "not" (see in- (1)) + gratus "pleasing, beloved, dear, agreeable" (see grace (n.)).
enroll (v.): mid-14c. (transitive), from Old French enroller "record in a register, write in a roll" (13c., Modern French enrôler), from en- "make, put in" (see en- (1)) + rolle (see roll (n.)). Related: Enrolled; enrolling.
ensample (n.): "precedent to be followed, illustrative instance; a pattern, model," c. 1300, variant of asaumple, from Old French essample "example" (see example). The survival of this variant form is due to its use in New Testament in KJV (1 Pet. v.3).
ensconce (v.): 1580s, "to cover with a fort," from en- (1) "make, put in" + sconce "small fortification, shelter," perhaps via French, probably from Dutch schans "earthwork" (compare Middle High German schanze "bundle of sticks"), which is of uncertain origin. Hence, "to fix firmly, settle" (1590s). Related: Ensconced.
ensure (v.): late 14c., from Anglo-French enseurer, from en- "make" (see en- (1)) + Old French seur "sure" (see sure); probably influenced by Old French asseurer "assure." Compare insure. Related: Ensured; ensures; ensuring.
marsupial (adj.): 1690s, with -al (1) + Modern Latin marsupialis "having a pouch," coined from Late Latin marsupium "pouch, purse" (Classical Latin marsuppium), from Greek marsipion, diminutive of marsipos "bag, pouch," of foreign, possibly oriental, origin. As a noun from 1805.
terrestrial (adj.): late 14c., "of or pertaining to the earth," with + -al (1) + from Latin terrestris "earthly, of the earth, on land," from terra "earth" (see terrain). Originally opposed to celestial; natural history sense of "living on land" is attested from 1630s. The noun meaning "a human being, a mortal" is recorded from 1590s.
tetrahedron (n.): "triangular pyramid, solid figure contained by four triangular surfaces," 1560s, from Late Greek tetraedron, noun use of neuter of tetraedros (adj.) "four-sided," from tetra- "four" (see tetra-) + hedra "seat, base, chair, face of a geometric solid," from PIE root *sed- (1) "to sit" (see sedentary). Related: Tetrahedral.
massive (adj.): c. 1400, from Middle French massif "bulky, solid," from Old French masse "lump" (see mass (n.1)). Related: Massively; massiveness. U.S. Cold War strategy of massive retaliation was introduced by J.F. Dulles in early 1954.
matron (n.): late 14c., "married woman" (usually one of rank), from Old French matrone "married woman; elderly lady; patroness; midwife," and directly from Latin matrona "married woman, wife, matron," from mater (genitive matris) "mother" (see mother (n.1)). Sense of "female manager of a school, hospital, etc." first recorded 1550s.
Paul: masc. proper name, Biblical name of the apostle to the Gentiles, from Latin Paulum (nominative Paulus), Roman surname of the Aemilian gens, literally "small," from PIE *pau-ro-lo-, from base *pau- (1) "few, little" (see few). Other forms include Old French Pol, Italian Paolo, Spanish Pablo, Russian Pavel.
pelagic (adj.): "pertaining to the sea," 1650s, from Latin pelagicus, from Greek pelagikos, from pelagos "sea, high sea, open sea, main," from PIE *pelag- "to spread out" (source of Greek plagos "side," Latin plaga "hunting net, curtain, region"), possibly from root *plak- (1) "to spread out, be flat" (see placenta).
Oscan (adj.): of or pertaining to the ancient people of southern Italy, 1590s, from Latin Osci, Opsci (plural) "Oscans," literally "worshippers of Ops," a harvest goddess, the name related to Latin ops (genitive opis) "abundance, plenty, wealth, riches," from PIE *op- (1) "to work, produce in abundance" (see opus).
overblown (adj.): late 15c., "blown over, passed away," past participle adjective from verb overblow "to blow over the top of," of a storm, "to abate, pass on" (late 14c.), from over- + blow (v.1). Meaning "inflated, puffed up" (with vanity, etc.) is from 1864.
Alma Mater (n.): late 14c., Latin, literally "bountiful mother," a title Romans gave to goddesses, especially Ceres and Cybele, from alma, fem. of almus "nourishing," from alere "to nourish" (see old) + mater "mother" (see mother (n.1)). First used 1710 in sense of "one's university or school" in reference to British universities.
biped (n.): "animal with two feet," 1640s, from Latin bipedem (nominative bipes) "two-footed," as a plural noun, "men;" from bi- "two" (see bi-) + pedem (nominative pes) "foot," from PIE root *ped- (1) "a foot" (see foot (n.)).
biplane (n.): airplane with two full wings, one above the other, 1874, as a theoretical notion; first attested 1908 in reference to the real thing; from bi- + plane (n.1). So called from the two "planes" of the double wings.
bird (n.2): "maiden, young girl," c. 1300, confused with burd (q.v.), but felt by later writers as a figurative use of bird (n.1). Modern slang meaning "young woman" is from 1915, and probably arose independently of the older word.
cheetah (n.): 1704, from Hindi chita "leopard," from Sanskrit chitraka "hunting leopard, tiger," literally "speckled," from chitra-s "distinctively marked, variegated, many-colored, bright, clear" (from PIE *kit-ro-, from root *(s)kai- (1) "bright, shining;" see shine (v.)) + kayah "body," from PIE *kwei- "to build, make" (see poet).
amiss (adv.): mid-13c., amis "off the mark," also "out of order," literally "on the miss," from a "in, on" (see a- (1)) + missen "fail to hit" (see miss (v.)). To take (something) amiss originally (late 14c.) was "to miss the meaning of" (see mistake). Now it means "to misinterpret in a bad sense."
amoeba (n.): 1855, from Modern Latin Amoeba, genus name (1841), from Greek amoibe "change," related to ameibein "to change, exchange," from PIE *e-meigw-, extended form of root *mei- (1) "to change, go, move" (see mutable). So called for its constantly changing shape. Related: Amoebaean; amoebic.
amount (v.): late 13c., "to go up, rise, mount (a horse)," from Old French amonter, from a mont "upward," literally "to the mountain," from Latin ad- "to" (see ad-) + montem (nominative mons) "mountain" (see mount (n.1)). Meaning "to rise in number or quality (so as to reach)" is from c. 1300. Related: Amounted; amounting.
escargot (n.): "edible snail," 1892, from French escargot, from Old French escargol "snail" (14c.), from Provençal escaragol, ultimately from Vulgar Latin *coculium, from classical Latin conchylium "edible shellfish, oyster" (see cockle (n.1)). The form of the word in Provençal and French seems to have been influenced by words related to scarab.
espresso (n.): coffee made under steam pressure, 1945, from Italian (caffe) espresso, from espresso "pressed out," past participle of esprimere, from Latin exprimere "press out, squeeze out" (see express (v.1)). In reference to the steam pressure.
chock-full (adj.): c. 1400, chokkeful "crammed full," possibly from choke "cheek" (see cheek (n.)). Or it may be from Old French choquier "collide, crash, hit" (13c., Modern French choquer), which is probably from Germanic (compare Middle Dutch schokken; see shock (n.1)).
disport (v.): late 14c., from Anglo-French disporter "divert, amuse," from Old French desporter "to seek amusement," literally "carry away" (the mind from serious matters), from des- "away" (see dis-) + porter "to carry," from Latin portare "to carry" (see port (n.1)). Compare disporter "a minstrel or jester" (early 15c.).
Himalaya: from Sanskrit himalayah, literally "abode of snow," from hima "snow," from PIE *ghi-mo-, from a possible PIE base for "winter" (see hibernation) + alayah "abode," derivative of layate "sticks, stays," from PIE root *(s)lei- "sticky" (see lime (n.1)). Related: Himalayas; Himalayan.
foolscap (n.): also fool's-cap, 1630s, "type of cap worn by a jester;" see fool (n.1) + cap (n.). From c. 1700 as a type of writing paper, so called because it originally was watermarked with a jester's cap.
intractable (adj.): c. 1500, "rough, stormy;" 1540s, "not manageable," from French intractable (15c.) or directly from Latin intractabilis "not to be handled, unmanageable," from in- "not, opposite of" (see in- (1)) + tractabilis (see tractable). Related: Intractably.
intransitive (adj.): 1610s, from Late Latin intransitivus "not transitive, not passing over" (to another person), Priscian's term, from in- "not" (see in- (1)) + Latin transitivus "that may pass over," from transire "to pass over" (see transitive). The noun meaning "an intransitive verb" is attested from 1824.
introspection (n.): 1670s, "action of closely inspecting or examining," noun of action from past participle stem of Latin introspicere "to look into, look at, examine, observe attentively," from intro- "inward" (see intro-) + specere "to look at" (see scope (n.1)). Meaning "action of searching one's feelings or thoughts" is from 1807.
invalid (adj.1): "not strong, infirm," also "infirm from sickness, disease, or injury", 1640s, from Latin invalidus "not strong, infirm, impotent, feeble, inadequate," from in- "not" (see in- (1)) + validus "strong" (see valid). With pronunciation from French invalide (16c.).
invaluable (adj.): 1570s, "above value, too valuable for exact estimate," from in- (1) "not" + value (v.) "estimate the worth of" + -able. It also has been used in a sense "without value, worthless" (1630s, from in- + valuable). Related: Invaluably.
inveigh (v.): formerly also enveigh, late 15c., "to introduce," from Latin invehere "to bring in, carry in, introduce," also "assault, assail," from in- "against" (see in- (1)) + vehere "to carry" (see vehicle). Meaning "to give vent to violent denunciation" is from 1520s, from a secondary sense in Latin (see invective). Related: Inveighed; inveighing.
irreverence (n.): mid-14c., from Old French irreverence (13c.) or directly from Latin irreverentia "want of reverence, disrespect," from irreverentem (nominative irreverens) "disrespectful, irreverent," from assimilated form of in- "not, opposite of" (see in- (1)) + reverens, present participle of revereri "to stand in awe of" (see revere).
homo- (1): before vowels hom-, word-forming element meaning "same, the same, equal, like" (opposed to hetero-), from Greek homos "one and the same," also "belonging to two or more jointly," from PIE *somo-, from root *sem- (1) "as one; together with" (see same).
homogeneous (adj.): 1640s, from Medieval Latin homogeneus, from Greek homogenes "of the same kind," from homos "same" (see homo- (1)) + genos "kind, gender, race, stock" (see genus). Earlier in this sense was homogeneal (c. 1600). Related: Homogeneously; homogeneousness.
homologous (adj.): "having the same position, value, structure, etc.," 1650s, from Latinized form of Greek homologos "agreeing, of one mind," from homos "same" (see homo- (1)) + logos "relation, reasoning, computation," related to legein "reckon, select, speak" (see lecture (n.)).
homonym (n.): "word pronounced and perhaps spelled the same as another but different in meaning," 1807, from French homonyme and directly from Latin homonymum (Quintilian), from Greek homonymon, neuter of homonymos, from homos "same" (see homo- (1)) + onyma, dialectal form of onoma "name" (see name (n.)). Related: Homonymic.
intestate (adj.): late 14c., from Old French intestat (13c.) and directly from Latin intestatus "having made no will," from in- "not" (see in- (1)) + testatus, past participle of testari "make a will, bear witness" (see testament). As a noun, "one who has not made out a will," from 1650s.
intolerable (adj.): late 14c., from Latin intolerabilis "that cannot bear; that cannot be borne," from in- "not, opposite of" (see in- (1)) + tolerabilis "that may be endured," from tolerare "to bear, endure" (see toleration). Related: Intolerably.
loch (n.): late 14c., from Gaelic loch "lake, narrow arm of the sea," cognate with Old Irish loch "body of water, lake," Breton lagen, Anglo-Irish lough, Latin lacus (see lake (n.1)). The Loch Ness monster is first attested 1933.
tidal (adj.): 1807, a hybrid formation from tide (n.) + Latin-derived suffix -al (1). A tidal wave (1819) properly is high water caused by movements of the tides; erroneous use for "tsunami, great ocean wave caused by an earthquake, etc." is recorded from 1868.
anacoluthon (n.): "want of grammatical sequence; changing constructions in mid-clause," 1706, from Latinized form of Greek anakoluthon, neuter of anakolouthos "inconsequent," from an- "not" (see an- (1)) + akolouthos "following," from copulative prefix a- + keleuthos "way, road, track, path" (see celerity).
ancillary (adj.): 1660s, "subservient, subordinate," from Latin ancillaris "relating to maidservants," from ancilla "handmaid," fem. diminutive of anculus "servant," literally "he who bustles about," from root of ambi- "about" (see ambi-) + PIE *kwol-o-, from root *kwel- (1) "move round, turn about, be much about" (see cycle (n.)).
anesthesia (n.): 1721, "loss of feeling," Modern Latin, from Greek anaisthesia "want of feeling, lack of sensation (to pleasure or pain)," from an- "without" (see an- (1)) + aisthesis "feeling," from PIE root *au- "to perceive" (see audience). With abstract noun ending -ia. As "a procedure for the prevention of pain in surgical operations," from 1846.
Anopheles (n.): genus of mosquitoes, Modern Latin, coined 1818 by German entomologist Johann Wilhelm Meigen (1764-1845) from Greek anopheles "useless, hurtful, harmful," from an-, privative prefix, (see an- (1)) + ophelos "use, help, advantage" (see Ophelia). So called because it conveys malaria.
menthol (n.): white crystalline substance, 1862, from German Menthol, coined 1861 by Alphons Oppenheim from Latin mentha "mint" (see mint (n.1)) + oleum "oil" (see oil (n.)). So called because it was first obtained from oil of peppermint.
mention (n.): c. 1300, "a note, reference," from Old French mencion "mention, memory, speech," from Latin mentionem (nominative mentio) "a calling to mind, a speaking of, a making mention," from root of Old Latin minisci "to think," related to mens (genitive mentis) "mind," from PIE root *men- (1) "think" (see mind (n.)).