Online Etymology Dictionary

penknife (n.): early 15c., from pen (n.1) + knife (n.). So called because such small knives were used to sharpen quills.
reparable (adj.): 1560s, from Middle French reparable (16c.), from Latin reparabilis "able to be restored or regained," from reparare "restore" (see repair (v.1)).
hover (v.): c. 1400, hoveren, frequentative of hoven "hover, tarry, linger;" see hove (v.1). Related: Hovered; hovering. As a noun from 1510s.
down (n.1): "soft feathers," late 14c., from Old Norse dunn, perhaps ultimately from PIE root *dheu- (1) "to fly about (like dust), to rise in a cloud."
piggyback (adj.): 1823, probably a folk etymology alteration of pick pack (1560s), which perhaps is from pick, a dialectal variant of pitch (v.1). As a verb from 1952.
apace (adv.): mid-14c., from a pace, literally "at a pace," but usually with a sense of "at a good pace," from a- (1) "on" + pace (n.).
methodical (adj.): 1560s, with -al (1) and methodic (1540s), from Middle French methodique, from Late Latin methodicus, from Greek methodikos, from methodos (see method). Related: Methodically.
cobble (v.): "to mend clumsily," late 15c., perhaps a back-formation from cobbler (n.1), or from cob, via a notion of lumps. Related: Cobbled; cobbling.
misfire (v.): 1752, of a gun, 1905, of an internal combustion engine; see mis- (1) + fire (v.). Related: Misfired; misfiring. The noun is attested from 1839.
mishap (n.): early 14c., "bad luck, unlucky accident," from mis- (1) "bad" + hap "luck." Probably on analogy of Old French meschance (see mischance (n.)).
triplicate (adj.): early 15c., "triple, threefold," from Latin triplicatus, past participle of triplicare "to triple," from tri- "three" (see tri-) + plicare "to fold" see ply (v.1)).
mothball (n.): also moth-ball, moth ball, "naphthalene ball stored among fabrics to keep off moths," 1891, from moth + ball (n.1).
router (n.): "cutter that removes wood from a groove," 1818, from rout "poke about, rummage" (1540s), originally of swine digging with the snout; a variant of root (v.1).
polity (n.): 1530s, from Middle French politie (early 15c.) or directly from Late Latin polita "organized government" (see policy (n.1)).
rubella (n.): "German measles," 1883, Modern Latin, literally "rash," from neuter plural of Latin rubellus "reddish," diminutive of ruber "red" (see red (adj.1)).
rucksack (n.): 1866, from German Rucksack, from Alpine dialect Rück "the back" (from German Rücken; see ridge) + Sack "sack" (see sack (n.1)).
rufous (adj.): "reddish-brown," 1782, from Latin rufus "red, reddish, tawny, red-haired," from an Osco-Umbrian cognate of Latin ruber "red" (see red (adj.1)).
misspend (v.): also mis-spend, "to spend amiss or wastefully," late 14c.; see mis- (1) + spend. Related: Misspent, frequently coupled with youth; misspending.
misuse (v.): late 14c., "to use improperly;" see mis- (1) + use (v.). Meaning "to subject to ill-treatment" is attested from 1530s. Related: Misused; misusing.
pinball (n.): also pin-ball, game played on a sloping surface, 1911, from pin (n.) + ball (n.1). Earlier it meant "a pincushion" (1803).
pipette (n.): also pipet, 1818, from French pipette, from Middle French pipette "tube," diminutive of Old French pipe, from Vulgar Latin *pipa (see pipe (n.1)).
service (v.): 1893, "to provide with service," from service (n.1). Meaning "perform work on" first recorded 1926. Related: Serviced; servicing.
smarten (v.): "to make smart, to spruce up, to improve appearance," 1786, from smart (adj.) in its sense of "spruce, trim" + -en (1). Related: Smartened; smartening.
short-timer (n.): "one whose term or enlistment is about to expire," 1906, from short (adj.) + time (n.) + agent noun ending -er (1).
straightforward (adj.): 1550s, "directly forward, right ahead," from straight (adj.1) + forward (adv.). In reference to language, from 1806. Related: Straightforwardly; straightforwardness.
thumbtack (n.): tack with a broad, flat head which may be driven by pressure from the thumb, 1884, from thumb (n.) + tack (n.1).
ZIP (adj.): 1963, in U.S. postal ZIP code, an acronym for Zone Improvement Plan, no doubt chosen with conscious echo of zip (v.1).
waterline (n.): also water-line, 1620s, line where the water rises to on the hull of a ship afloat, from water (n.1) + line (n.).
windbag (n.): late 15c., "bellows for an organ," from wind (n.1) + bag (n.). Figurative sense of "person who talks too much" is attested from 1827.
update (v.): 1944, in reference to information, 1952 in reference to persons, from up (adv.) + date (v.1). Related: Updated; updating. The noun is attested from 1967.
unblemished (adj.): c. 1300, from un- (1) "not" + past participle of blemish (v.). Originally in moral sense; material sense is attested from mid-15c.
unvarnished (adj.): c. 1600, of statements, "not embellished," from un- (1) "not" + past participle of varnish (v.). Literal sense of "not covered in varnish" is recorded from 1758.
unwell (adj.): mid-15c., "somewhat ill," from un- (1) "not" + well (adj.). Similar formation in North Frisian unwel, German unwohl.
unwholesome (adj.): c. 1200, from un- (1) "not" + wholesome (adj.). Similar formation in Flemish onheylsaem, German unheilsam, Old Norse uheilsamr.
unruffled (adj.): 1650s in figurative sense, from un- (1) "not" + past participle of ruffle (v.). Literal meaning, in reference to feathers, leaves, etc., is recorded from 1816.
unrefined (adj.): 1590s, "not refined in manners," from un- (1) "not" + past participle of refine (v.). Meaning "not free from gross matter" is recorded from 1610s.
unpracticed (adj.): also unpractised, 1550s, "unexpert," of persons, from un- (1) "not" + past participle of practice (v.). From 1530s as "not done, untried."
unsalted (adj.): mid-15c., from un- (1) "not" + past participle of salt (v.). Similar formation in North Frisian unsalted, Swedish osaltad, Danish usaltet.
unseasonable (adj.): mid-15c., "inopportune," from un- (1) "not" + seasonable (adj.). In reference to weather, "not appropriate to the time of year," it is recorded from 1510s. Related: Unseasonably.
unseemly (adj.): early 14c., "unfitting, indecent," from un- (1) "not" + seemly (adj.). Similar formation in Old Norse usoemiligr. Related: Unseemliness.
unstrung (adj.): 1590s, "with strings relaxed" (of a harp, etc.), from un- (1) "not" + past participle of string (v.). Transferred sense of "weakened, unnerved" is recorded from 1690s.
unspoken (adj.): late 14c., from un- (1) "not" + past participle of speak (v.). Similar formation in Middle Dutch ongesproken, Middle Low German ungesproken.
unsolicited (adj.): 1580s, "unpetitioned, not approached with a request," from un- (1) "not" + past participle of solicit (v.). Meaning "not asked for, unsought" is from 1680s.
unspeakable (adj.): c. 1400, "inexpressible," from un- (1) "not" + speakable (see speak (v.)). Meaning "indescribably bad or wicked" is recorded from mid-15c. Related: Unspeakably.
unimproved (adj.): 1660s, "not made better," from un- (1) "not" + past participle of improve (v.). Sense of "not developed or taken advantage of" (of land) is recorded from 1781.
unleaded (adj.): 1610s, "having no lead," from un- (1) "not" + leaded (see lead (v.2)). In reference to gasoline, from 1965. In reference to printing, from 1902.
unlettered (adj.): mid-14c., "not possessed of book-learning," from un- (1) "not" + lettered. An Englished form of illiterate. Similar formation in Middle Dutch ongelettert.
unmarried (adj.): c. 1300, from un- (1) "not" + past participle of marry (v.). In former use most often applied to one who has never married.
unoriginal (adj.): 1660s, "uncreated, without an origin," from un- (1) "not" + original (adj.). Meaning "derivative, second-hand" is recorded from 1774. Related: Unoriginality.
undefended (adj.): 1560s, "not defended, unprotected," from un- (1) "not" + past participle of defend (v.). Attested earlier in a now-obsolete sense of "unforbidden" (late 14c.).