Online Etymology Dictionary

ruddy (adj.): late Old English rudig "rubicund," probably from rudu "redness," related to read "red" (see red (adj.1)). As a British slang euphemism for bloody (q.v.), first recorded 1914. Related: Ruddiness.
buckaroo (n.): 1889, American English, from bakhara (1827), from Spanish vaquero "cowboy," from vaca "cow," from Latin vacca (see vaccination). Spelling altered by influence of buck (n.1).
mistime (v.): late Old English mistimian "to happen amiss" (of an event); see mis- (1) + time (v.). Meaning "not to time properly" is first recorded late 14c. Related: Mistimed; mistiming.
pippin (n.): "excellent person or thing," 1897, from coveted varieties of apple that were raised from seed (so called since early 15c.), from Middle English pipin "seed" (see pip (n.1)).
spatial (adj.): 1840 (spacial is from 1838), "occupying space," from Latin spatium + adjectival suffix -al (1); formed in English as an adjective to space (n.), to go with temporal. Meaning "of or relating to space" is from 1857. Related: Spatially.
-sis: suffix in Greek-derived nouns denoting action, process, state, condition, from Greek -sis, which is identical in meaning with Latin -entia, English -ing (1).
smacker (n.): "money," c. 1918, American English slang, perhaps from smack (v.1) on notion of something "smacked" into the palm of the hand. Extended form smackeroo is attested from 1939.
wholesome (adj.): c. 1200, "of benefit to the soul," from whole (adj.) in the "healthy" sense + -some (1). Physical sense first attested late 14c. Related: Wholesomely; wholesomeness. Old English had halwende.
unborn (adj.): Old English unboren "not yet born; stillborn," from un- (1) "not" + born. Similar formation in Old Frisian unbern, Dutch ongeboren, Old High German ungiporan, German ungeboren.
unbidden (adj.): Old English unbedene, "not asked or invited," from un- (1) "not" + bidden. Similar formation in Middle Dutch ongebeden, German ungebeten, Old Norse ubeðinn.
unsaid (adj.): Old English unsæd, from un- (1) "not" + past participle of say (v.). Similar formation in Middle Dutch ongeseit, German ungesagt, Old Norse usagðr.
unseen (adj.): early 13c., from un- (1) "not" + seen. Similar formation in Old English ungesewen, Middle Dutch ongesien, Dutch ongezien, Old High German ungesëhan, German ungesehen, Old Norse usenn.
unwise (adj.): Old English unwis, from un- (1) "not" + wise (adj.). Similar formation in Middle Dutch onwijs, Old High German unwis, German unweise, Old Norse uviss, Gothic unweis.
untainted (adj.): 1580s, in the moral sense; c. 1600 in the physical sense; from un- (1) "not" + past participle of taint (v.). Earlier was untained (mid-15c.), from a Middle English variant of taint (v.).
untamed (adj.): mid-14c., from un- (1) "not" + past participle of tame (v.). Similar formation in Old English untemed, Old Norse utamdr, Old High German ungizamot.
untimely (adj.): 1530s, "coming before the proper or usual time," from un- (1) "not" + timely (adj.). Similar formation in Middle Danish utimelig, of weather, etc. Old English had untidlic "unseasonable." Related: Untimeliness.
untruth (n.): Old English untreowþ "unfaithfulness, treachery," from un- (1) "not" + truth (n.). Similar formation in Old Norse utrygð. Meaning "falsehood" is attested from mid-15c., as is that of "a lie." Related: Untruthful.
unlike (adj.): c. 1200, "not resembling," from un- (1) "not" + like (adj.). Similar formation in Old English ungelic, Old Frisian unlik, Old Norse ulikr, Middle Danish ulige, German ungleich.
unlawful (adj.): "contrary to law, illegal," c. 1300, from un- (1) "not" + lawful. Unlawful assembly is recorded in statutes from late 15c. Related: Unlawfully. Old English had a noun unlagu ("unlaw") "illegal action, abuse of law."
undead (adj.): "neither dead nor alive," c. 1400, from un- (1) "not" + dead. As a noun meaning "vampires and such," from 1904. Old English undeadlic (adv.) meant "immortal, for all eternity."
unbelief (n.): mid-12c., "absence or lack of religious belief; disbelief of the truth of the Gospel," from un- (1) "not" or un- (2) "opposite of" + belief. Old English had ungeleafa in this sense.
unmeet (adj.): Old English unmæte "immoderate, excessive," from un- (1) "not" + meet (adj.). Similar formation in Old High German unmazi. Meanings "unfitting" and "unsuited" (for some purpose) are from 1520s.
stockade (n.): 1610s, "a barrier of stakes," a nativization of Spanish estacada, from estaca "stake," from a Germanic source cognate with Old English staca, see stake (n.1)). Meaning "military prison" first recorded 1865. As a verb from 1755.
sawbuck (n.): "ten-dollar bill," American English slang, 1850, from resemblance of X (Roman numeral 10) to the ends of a sawhorse. Sawbuck in the sense of "sawhorse" is attested only from 1862 but presumably is older (see saw (n.1)).
steenbok (n.): 1775, from Afrikaans steenbok, from Middle Dutch steenboc "wild goat," literally "stone buck," cognate with Old English stanbucca "mountain goat," German Steinbock. See stone (n.) + buck (n.1).
seventy: Old English (hund)seofontig, from seofon (see seven) + -tig (see -ty (1)). Similar formation in Old Frisian soventich, Middle Dutch seventich, Old Norse sjau tiger.
brighten (v.): Old English *beorhtnian "to make bright" (see bright (adj.) + -en (1)). Intransitive sense, "to become brighter," attested from c. 1300. Figurative use from 1590s. Related: Brightened; brightening.
brulee (adj.): from French brûlée "burned," from brûler, from Old French brusler (11c.); see broil (v.1). Crème brûlée was known in English by various names from early 18c., including a translated burnt cream.
boardwalk (n.): "walkway made of boards," 1864, American English, from board (n.1) + walk (n.). As a seaside attraction from 1881, first in reference to Atlantic City, N.J.
utterly (adv.): early 13c., "truly, plainly, outspokenly," from utter (v.) + -ly (1); meaning "to an absolute degree" is late 14c., from utter (adj.)). Cf similarly formed German äusserlich. Old English uterlic (adj.) meant "external."
tribal (adj.): 1630s, "pertaining to or characteristic of tribes," from tribe + -al (1). Meaning "characterized by a strong sense of loyalty to one's group" is from 1951 (Arendt). As a style of belly-dance from 1999, American English. Related: Tribally.
unbeliever (n.): "one who does not believe in any given religion," 1520s, from un- (1) "not" believer. Old English had ungelifend in this sense.
trouper (n.): 1890, "actor or performer in a troupe," from troupe (n.) + -er (1). Transferred sense of "reliable, uncomplaining person" [OED] is attested by 1942, American English.
fiftieth (adj.): Old English fifteogoða "fiftieth;" see fifty + -th (1). Compare Old Norse fimmtugande, and, with a different suffix, Old Frisian fiftichsta, Dutch vijftigste, Old High German fimfzugsto, German fünfzigste.
unthrifty (adj.): late 14c., "unprofitable, useless," from un- (1) "not" + thrifty (adj.), or else from Middle English noun unthrift "profligacy," late 14c., earlier "evil practice, wicked act" (c. 1300).
whistleblower (n.): also whistle-blower, 1963 in the figurative sense, American English, from whistle (n.) as something sounded in an alert + agent noun from blow (v.1).
fourteenth (adj.): c. 1300, fourtenethe; see fourteen + -th (1). By influence of fourteen, replacing or modifying fourtende, fowrtethe, from Old English feowerteoða, Old Norse *feowertandi "fourteenth." Compare Dutch veertiende, German vierzehnte.
logjam (n.): also log-jam, "congestion of logs on a river," by 1851, American English; see log (n.1) + jam (v.). The figurative sense is by 1890.
handlebar (n.): also handle-bar, 1867 in reference to bicycles, from handle (n.) + bar (n.1). Handlebar mustache is from 1932, American English, from similarity of shape; the comparison, if not the phrase, dates to at least 1911.
pathological (adj.): 1680s, "pertaining to disease," formed in English from pathologic + -al (1). Sense of "worthy to be a subject of pathology, morbid, excessive" (as in pathological liar) is attested from 1845. Related: Pathologically.
leaden (adj.): "made of lead," Old English leaden, from lead (n.1) + -en (2). The figurative sense of "heavy, oppressive, dull" is attested by 1570s. Related: Leadenly; leadenness.
cun (v.): "to learn to know, inquire into," from Old English cunnian "to learn to know," ultimately from the same ancient root as can (v.1). Surviving into 17c. and perhaps later in dialects.
coulter (n.): Old English culter, from Latin culter "a knife, iron blade in a plowshare," from PIE root *(s)kel- "to cut" (see scale (n.1)). As a surname (13c.), probably from Coulter in Lancashire.
earthly (adj.): Old English eorþlic "worldly, pertaining to this world" (as opposed to spiritual or heavenly"); see earth (n.) + -ly (1). The sense "belonging to or originating in the earth" is from mid-15c.
eighth: late 14c., eighthe, contracted from Old English eahtoða; see eight + -th (1). Cognate with Old High German ahtoda, Old Frisian achta, German achte, Gothic ahtuda.
downright (adv.): c. 1200, "straight down," from down (adv.) + right (adj.1). Meaning "thoroughly" attested from c. 1300. Old English had dunrihte "downwards," and inverted form right-down is attested 17c.
comical (adj.): early 15c., "comic," from comic (or Latin comicus) + -al (1). Meaning "funny" is from 1680s. Earlier Middle English had an identical word meaning "epileptic," from Latin morbus comitialis "epilepsy."
ghostly (adj.): Old English gastlic "spiritual, holy, not of the flesh; clerical;" also "supernatural, spectral, pertaining to or characteristic of a ghost;" see ghost (n.) + -ly (1). Related: Ghostliness.
hearten (v.): 1520s, "put heart into" (transitive), from heart (n.) in the figurative sense + -en (1). Intransitive sense "to cheer up" is from 1708. Related: Heartened; heartening. Earlier verb was simply heart (Old English).
harden (n.): c. 1200, transitive, "make (something) hard," from hard (adj.) + -en (1). Intransitive meaning "to become hard" is late 14c. The earlier verb was simply hard, from Old English heardian. Related: Hardened; hardening.