Online Etymology Dictionary

uncertain (adj.): c. 1300, "of indeterminate time or occurrence," from un- (1) "not" + certain (adj.). Meaning "not fully confident" is recorded from late 14c. (implied in uncertainty). Related: Uncertainly.
uncalled (adj.): c. 1400, "not summoned," from un- (1) "not" + past participle of call (v.). Similar formation in Swedish okallad, Danish ukaldet. With for and sense of "unnecessary, intrusive" it is first attested 1610.
undaunted (adj.): mid-15c., with reference to horses, "untamed, not broken in," from un- (1) "not" + past participle of daunt (v.). In reference to persons, "intrepid," it is recorded from 1580s.
undefiled (adj.): c. 1300, undefylde, from un- (1) "not" + past participle of defile (v.). Originally of morals; sexual sense is attested from mid-15c. Physical sense of "not made dirty" is from 1580s.
unfit (adj.): 1540s, "not suitable" (in reference to things), from un- (1) "not" + fit (adj.). Related: Unfitness. In reference to persons or human qualities, attested from 1550s.
unfledged (adj.): c. 1600, of persons, "immature, not experienced," from un- (1) "not" + past participle of fledge (v.). Literal sense of "not yet covered in feathers" is recorded from 1610s.
unfurnished (adj.): 1540s, "not equipped, unprepared," from un- (1) "not" + past participle of furnish (v.). In reference to houses, apartments, etc., "not provided with furniture," it is recorded from 1580s.
unawares (adv.): 1530s, "without being aware," from un- (1) "not" + aware + adverbial genitive -s. Meaning "without being noticed" is recorded from 1660s. Form unaware is recorded from 1590s.
unaccustomed (adj.): 1520s, "not customary, unfamiliar," from un- (1) "not" + past participle of accustom (v.). Meaning "not accustomed or habituated" (to) is first attested 1610s (see accustomed).
uncomfortable (adj.): early 15c. "causing bodily or mental discomfort, affording no comfort," from un- (1) "not" + comfortable (adj.). Intransitive meaning "feeling discomfort, ill-at-ease" is attested from 1796. Related: Uncomfortably.
unchurched (adj.): 1680s, from un- (1) "not" + churched "committed or belonging to a church" (see church (v.)). A verb, unchurch "to remove or exclude (someone) from membership in a church" is recorded from 1610s.
aboriginal (adj.): 1660s, "first, earliest," especially in reference to inhabitants of lands colonized by Europeans, from aborigines (see aborigine) + -al (1); specific Australian sense is from 1820. The noun is attested from 1767. Related: Aboriginally.
apodal (adj.): 1769, with -al + Greek apous (genitive apodos) "footless," from a-, privative prefix (see a- (3)) + pous "foot," from PIE root *ped- (1) "a foot" (see foot (n.)).
air conditioner (n.): from air (n.1) + agent noun from condition; along with air-conditioning, first attested 1909, originally an industrial process; main modern use in residences and office buildings is from 1930s.
airhead (n.): "empty-headed person," 1972, from air (n.1) + head (n.). Earlier as a term in mining (mid-19c.) and as a military term based on beachhead (1950).
ataraxia (n.): also Englished as ataraxy, "calmness, impassivity," c. 1600, from Modern Latin, from Greek ataraxia "impassiveness," from a-, privative prefix, + tarassein (Attic tarattein) "to disturb, confuse," from PIE root *dher- (1) "to make muddy, darken."
anemia (n.): alternative (chiefly U.S.) spelling of anaemia (q.v.). See ae. As a genus of plants, Modern Latin, from Greek aneimon "unclad," from privative prefix an- (see an- (1)) + eima "a dress, garment" (see wear (v.)).
analgesia (n.): "absence of pain," 1706, medical Latin, from Greek analgesia "painlessness, insensibility," from analgetos "without pain, insensible to pain" (also "unfeeling, ruthless"), from an- "not" (see an- (1)) + algein "to feel pain" (see -algia).
aboveboard (adj.): 1610s, from above and board (n.1). "A figurative expression borrowed from gamesters, who, when they put their hands under the table, are changing their cards." [Johnson]
aneuploidy (n.): abnormal number of chromosomes, 1934, from aneuploid (1931), Modern Latin, coined 1922 by G. Täckholm from an- (1) "not" + euploid, from Greek eu- "well, good" (see eu-) + -ploid, from ploos "fold" (see -plus) + -oid.
anomy (n.): "lawlessness," 1590s, Englished from French anomie; from Greek anomia "lawlessness," noun of quality from anomos "without law, lawless," from a-, privative prefix, "without" (see an- (1)) + nomos "law" (see numismatic).
anosmia (n.): "loss of sense of smell," 1811, Modern Latin, from Greek an-, privative prefix (see an- (1)), + osme "smell" (Doric odme), from *odsme, cognate with Latin odor (see odor) + abstract noun ending -ia.
antedate (v.): 1580s, earlier as noun meaning "a backdating, false early date attached to a document or event" (1570s); from Latin ante "before" (see ante) + date (v.1). Related: Antedated; antedating.
satchel (n.): "small bag," mid-14c., from Old French sachel, from Late Latin saccellum "money bag, purse," diminutive of Latin sacculus, diminutive of saccus "bag" (see sack (n.1)).
stele (n.): "upright slab," usually inscribed, 1820, from Greek stele "standing block, slab," especially one bearing an inscription, such as a gravestone, from PIE root *stel- "to put, stand" (see stall (n.1)). Related: Stelar.
sackcloth (n.): penitential or grieving garb, late 13c., literally "cloth of which sacks are made," from sack (n.1) + cloth. In the Biblical sense it was of goats' or camels' hair, the coarsest possible clothing.
stripling (n.): "a youth," late 14c., of uncertain origin, possibly from strip (n.1) "long, narrow piece," on the notion of "one who is slender as a strip, whose figure is not yet filled out" + -ling.
surcingle (n.): "girth for a horse" or other animal, late 14c., from Old French surcengle, from sur- "over" (see sur- (1)) + cengle "a girdle," from Latin cingulum "girth" (see cinch (n.)).
surcoat (n.): "outer coat," early 14c., from Old French surcote "outer garment," from sur- "on, upon, over, above" (see sur- (1)) + cote (see coat (n.)).
surpass (v.): 1550s, from Middle French surpasser "go beyond, exceed, excel" (16c.), from sur- "beyond" (see sur- (1)) + passer "to go by" (see pass (v.)). Related: Surpassed; surpassing.
azalea (n.): type of flowering shrub, 1753, Modern Latin, coined by Linnaeus from the fem. of Greek azaleos "dry," related to azein "to dry up" (see ash (n.1)). The plant thrives in sandy soil.
core (n.): late 14c., probably from Old French coeur "core of fruit, heart of lettuce," literally "heart," from Latin cor "heart," from PIE root *kerd- (1) "heart" (see heart (n.)). Nuclear reactor sense is from 1949.
corn (n.2): "hardening of skin," early 15c., from Old French corne (13c.) "horn (of an animal)," later, "corn on the foot," from Latin cornu "horn," from PIE *ker- (1) "horn; head, uppermost part of the body" (see horn (n.)).
shoat (n.): also shote, "a young weaned pig," early 15c., perhaps from a Low German word (compare West Flemish schote "pig under 1 year old"), of unknown origin.
scholiast (n.): "one who writes explanatory notes upon a classical writer," 1580s, from Late Latin scholiasta, from Late Greek skholiastes, from skholiazein, from skholion "explanatory note or comment," from skhole (see school (n.1)). Related: Scholiastic.
scope (n.2): "instrument for viewing," 1872, abstracted from telescope, microscope, etc., from Greek skopein "to look" (see scope (n.1)). Earlier used as a shortening of horoscope (c. 1600).
shtick (n.): also schtick, 1959, from Yiddish shtik "an act, gimmick," literally "a piece, slice," from Middle High German stücke "piece, play," from Old High German stucki (see stock (n.1)).
slovenly (adj.): 1510s, "low, base, lewd," later "untidy, dirty" (1560s), from sloven + -ly (1). Related: Slovenliness; also in this sense was slovenry (1540s), which OED reports in common use early 17c.
skewer (n.): 1670s, variant of dialectal skiver (1660s), perhaps from a Scandinavian source such as Old Norse skifa "a cut, slice" (of bread, etc.), Swedish skifer "a slate," which are related to shiver (n.1) "small piece."
scrap (n.2): "fight," 1846, possibly a variant of scrape (n.1) on the notion of "an abrasive encounter." Weekley and OED suggest obsolete colloquial scrap "scheme, villainy, vile intention" (1670s).
auricle (n.): part of the ear, 1650s, from Latin auricula "ear," diminutive of auris (see ear (n.1)). As a chamber of the heart, early 15c., from Latin, so called from a perceived similarity in shape to an animal's ear.
canonical (adj.): early 15c., "according to ecclesiastical law," from Medieval Latin canonicalis, from Late Latin canonicus "according to rule," in Church Latin, "pertaining to the canon" (see canon (n.1)). Earlier was canonial (early 13c.).
canonize (v.): late 14c., "to place in the canon or calendar of saints," from Old French cannonisier and directly from Medieval Latin canonizare, from Late Latin canon "church rule" (see canon (n.1)). Related: Canonized; cannonizing.
boredom (n.): "state of being bored," 1852, from bore (v.1) + -dom. It also has been employed in a sense "bores as a class" (1883) and "practice of being a bore" (1864, a sense properly belonging to boreism, 1833).
brickbat (n.): mid-16c., piece of brick (half or less) used as a missile, from brick (n.) + bat (n.1). Figurative use, of comments, insults, etc., is from 1640s.
blazing (adj.): late 14c., "shining," also "vehement," present participle adjective from blaze (v.1). As a mild or euphemistic epithet, attested from 1888 (no doubt connected with the blazes in colloquial sense of "Hell").
buckskin (n.): c. 1300, "skin of a buck," from buck (n.1) + skin (n.). Meaning "leather made from buckskin" was in use by 1804. The word was a nickname for Continental troops in the American Revolution.
bullseye (n.): also bulls-eye, 1833, "center of a target," from bull (n.1) + eye (n.). So called for size and color. Meaning "shot that hits the mark" is from 1857.
butthole (n.): also butt-hole, "anus," 1950s slang, from butt (n.1) + hole (n.). Earlier it meant "blind hole; cul-de-sac" (early 20c.).
blueprint (n.): also blue-print, 1882, from blue (1) + print (n.). The process uses blue on white, or white on blue. Figurative sense of "detailed plan" is attested from 1926. As a verb by 1939.