Online Etymology Dictionary

impediment (n.): c. 1400, from Old French empedement or directly from Latin impedimentum "hindrance," from impedire "impede," literally "to shackle the feet," from assimilated form of in- "into, in" (see in- (2)) + pes (genitive pedis) "foot," from PIE root *ped- (1) "a foot" (see foot (n.)). Related: Impedimental.
impel (v.): early 15c., from Latin impellere "to push, strike against; set in motion, drive forward, urge on," from assimilated form of in- "into, in, on, upon" (see in- (2)) + pellere "to push, drive" (see pulse (n.1)). Related: Impelled; impelling.
impersonal (adj.): mid-15c., a grammatical term, from Late Latin impersonalis, from assimilated form of in- "not, opposite of" (see in- (1)) + personalis "personal" (see personal). Sense of "not connected with any person" is from 1620s; that of "not endowed with personality, having no conscious individuality" is from 1842. Related: impersonally.
imperturbable (adj.): c. 1500, from Middle French imperturbable (15c.) and directly from Late Latin imperturbabilis "that cannot be disturbed" (Augustine), from assimilated form of in- "not, opposite of" (see in- (1)) + *perturbabilis, from Latin perturbare "to confuse, disturb" (see perturb). Related: Imperturbably (1785); imperturbability (1831; earlier as a dictionary word); imperturbation.
impolite (adj.): 1610s, "unrefined, rough," from Latin impolitus "unpolished, rough, inelegant, unrefined," from assimilated form of in- "not, opposite of" (see in- (1)) + politus "polished" (see polite). Sense of "discourteous, uncivil, unpolished in manners" is from 1739. Related: Impolitely.
impregnable (adj.): early 15c., imprenable "impossible to capture," from Old French imprenable "invulnerable," from assimilated form of in- "not, opposite of" (see in- (1)) + Old French prenable "assailable, vulnerable" (see pregnable). With restored -g- from 16c. Related: Impregnably.
impudent (adj.): late 14c., from Latin impudentem (nominative impudens) "without shame, shameless," from assimilated form of in- "not, opposite of" (see in- (1)) + pudens "ashamed, modest," present-participle adjective from pudere "to cause shame" (see pudendum). Related: Impudently.
impunity (n.): 1530s, from Middle French impunité (14c.) and directly from Latin impunitatem (nominative impunitas) "freedom from punishment, omission of punishment," also "rashness, inconsideration," from impunis "unpunished, without punishment," from assimilated form of in- "not, opposite of" (see in- (1)) + poena "punishment" (see penal).
-latry: word-forming element meaning "worship of," used as an element in native formations from 19c. (such as bardolatry), from Greek -latreia "worship, service paid to the gods, hired labor," related to latron (n.) "pay, hire," latris "servant, worshipper," from PIE *le- (1) "to get" (see larceny).
Mace (n.3): chemical spray originally used in riot control, 1966, technically Chemical Mace, a proprietary name (General Ordnance Equipment Corp, Pittsburgh, Pa.), probably so called for its use as a weapon, in reference to mace (1). The verb is first attested 1968. Related: Maced; macing.
lanolin (n.): fatty matter extracted from sheep's wool, 1885, from German Lanolin, coined by German physician Mathias Eugenius Oscar Liebreich (1838-1908) from Latin lana "wool" (from PIE root *wele- (1) "wool;" see wool) + oleum "oil, fat" (see oil (n.)) + chemical suffix -in (2).
propel (v.): mid-15c., "to drive away, expel," from Latin propellere "push forward, drive forward, drive forth; move, impel," from pro- "forward" (see pro-) + pellere "to push, drive" (see pulse (n.1)). Meaning "to drive onward, cause to move forward" is from 1650s. Related: Propelled; propelling.
propose (v.): mid-14c., from Old French proposer "propose, advance, suggest" (12c.), from pro- "forth" (see pro-) + poser "put, place" (see pose (v.1)). Meaning "make an offer of marriage" is first recorded 1764. Related: Proposed; proposing. See also propone, which coexisted with this word for a time.
pulsar (n.): 1968, from pulse (n.1), the form on analogy of quasar. When discovered in 1967, they were thought perhaps to be signals from alien civilizations and astronomers informally dubbed them LGM for "Little Green Men."
pulse (n.2): "peas, beans, lentils," late 13c., from Old French pouls, pols and directly from Latin puls "thick gruel, porridge, mush," probably via Etruscan, from Greek poltos "porridge" made from flour, from PIE *pel- (1) "dust, flour" (see pollen; also compare poultice).
Punjab: region on the Indian subcontinent, from Hindi Panjab, from Persian panj "five" (from PIE *penkwo-; see five) + ab "water," from Iranian *ap-, from PIE *ap- (2) "water" (see water (n.1)). So called for its five rivers. Related: Punjabi.
purport (n.): early 15c., from Anglo-French purport (late 13c.), Old French porport "contents, tenor," back-formation from purporter "to contain, convey, carry," from pur- (from Latin pro- "forth;" see pur-) + Old French porter "to carry," from Latin portare "to carry" (see port (n.1)).
offing (n.): in phrase in the offing, 1779, from nautical term offing "the more distant part of the sea as seen from the shore" (1620s), from off (q.v.) + noun suffix -ing (1). Originally the phrase meant "in the distant future;" modern sense of "impending" developed 1914.
unfortunate (adj.): mid-15c., "unlucky," from un- (1) "not" + fortunate (adj.). Infortunate in same sense is older. In late 18c.-early 19c., unfortunate woman was a polite way to say "prostitute." The noun meaning "one who is not fortunate" is recorded from 1630s.
ungodly (adj.): late 14c., "irreligious, not god-fearing, not in accordance with the laws of God," from un- (1) "not" + godly (adj.). Similar formation in Middle Dutch ongodelijc, German ungöttlich, Middle Swedish ogudhlik. Colloquial sense of "extremely annoying" is recorded from 1887.
Upanishad (n.): one of a class of speculative treatises in Sanskrit literature, 1805, from Sanskrit upa-nishad, literally "a sitting down beside." From upa "near to" (see up (adv.)) + ni-shad "to sit or lie down," from ni "downward" (from PIE *ni-, see nether) + -sad "sitting," From PIE *sed- (1) "to sit" (see sedentary).
tarmac (n.): 1903, Tarmac, a trademark name, short for tarmacadam (1882) "pavement created by spraying tar over crushed stone," from tar (n.1) + John L. McAdam (see macadam). By 1919, tarmac was being used generally in Great Britain for "runway."
tarpaulin (n.): c. 1600, evidently a hybrid from tar (n.1) + palling, from pall "heavy cloth covering" (see pall (n.)); probably so called because the canvas sometimes is coated in tar to make it waterproof. Originally tarpawlin, tarpawling, etc., the spelling settled down early 18c.
ultramontane (adj.): 1590s, from Middle French ultramontain "beyond the mountains" (especially the Alps), from Old French (early 14c.), from Latin ultra "beyond" (see ultra-) + stem of mons (see mount (n.1)). Used especially of papal authority, though "connotation varies according to the position of the speaker or writer." [Weekley]
uncial (adj.): 1640s, "pertaining to an ounce," from Latin uncialis "of an inch, of an ounce," from uncia "a twelfth part" (see inch (n.1)). In reference to letters, it is attested from 1712, from Late Latin litterae unciales (Jerome), probably meaning "letters an inch high," from Latin uncialis "of an inch, inch-high." As a noun, "an uncial letter," from 1775.
unconscious (adj.): 1712, "unaware, not marked by conscious thought," from un- (1) "not" + conscious. Meaning "temporarily insensible, knocked out" is recorded from 1860. Related: Unconsciously; unconsciousness. In psychology, the noun the unconscious (1876) is a loan-translation of German das Unbewusste. The adjective in this sense is recorded from 1912.
uncut (adj.): early 15c., "not gashed or wounded," from un- (1) "not" + past participle of cut (v.). Of books, "not having the leaves slit open" it is recorded from 1828; of plays, etc., "without excisions," it is attested from 1896.
underarm (adj.): 1816, "underhand" (in reference to a style of throwing), from under + arm (n.1). First attested 1908 in dressmaking sense of "seams on the lower half of the arm-hole;" as a euphemism for armpit, it is attested from 1930s, popularized by advertisers.
palliard (n.): late 15c., "vagabond or beggar" (who sleeps on straw in barns), from Middle French paillard, from Old French paillart "tramp, beggar, vagabond" (13c.), from paille "straw" (see pallet (n.1); also see -ard).
pamper (v.): late 14c., "to cram with food," probably from Middle Dutch (compare West Flemish pamperen "cram with food, overindulge;" dialectal German pampen "to cram"), probably from frequentative of root of pap (n.1). Meaning "to overindulge" first attested 1520s. Related: Pampered; pampering.
rara avis (n.): c. 1600, "peculiar person," from Latin rara avis, literally "strange bird," from rara, fem. of rarus "rare" (see rare (adj.1)) + avis "bird" (see aviary). Latin plural is raræ aves. Horace's peacock (a Roman delicacy), Juvenal's black swan ("Rara avis in terris, nigroque simillima cygno").
vamp (v.): "extemporize on a piano," 1789, from vamp (n.1) "upper part of a shoe or boot," via verbal sense of "provide a stocking (later a shoe) with a new vamp" (1590s), then "patch up, repair" (compare revamp). Related: Vamped; vamping.
Velox (n.): type of photographic print paper made by a process patented 1893 by Leo Baekeland, who sold it to George Eastman in 1899 for $1 million and used the money to build the laboratory where he made great discoveries in plastics (see Bakelite).
vend (v.): 1620s, from Latin vendere "to sell, give for a bribe; praise, cry up," contraction of venumdare "offer for sale," from venum "for sale" (see venal) + dare "to give" (see date (n.1)). Related: Vended; vending; vendible (early 14c.). Vending machine is recorded from 1889.
rack (n.2): type of gait of a horse, 1580s, from rack (v.) "move with a fast, lively gait" 1520s in this sense (implied in racking), of unknown origin; perhaps from French racquassure "racking of a horse in his pace," itself of unknown origin. Or perhaps a variant of rock (v.1).
raconteur (n.): "storyteller, person skilled in relating anecdotes," 1828, from French raconteur, from raconter "to recount, tell, narrate," from re- (see re-) + Old French aconter "to count, render account" (see account (v.); and compare recount (v.1)). Related: Raconteuse (fem.).
filament (n.): "fine untwisted thread, separate fibril," 1590s, from Modern Latin filamentum, from Late Latin filare "to spin, draw out in a long line," from Latin filum "thread" (see file (v.1)). As the name of the incandescent element in a light-bulb, from 1881.
fillet (n.): early 14c., "little headband," from Old French filet "thread, filament; strip, ligament" (12c.), diminutive of fil "thread" (see file (v.1)). Sense of "cut of meat or fish" is from late 14c., apparently so called because it was prepared by being tied up with a string.
Jonah: masc. proper name, biblical prophet and subject of the Book of Jonah, from Hebrew Yonah, literally "dove, pigeon." In nautical use (and extended) "person on shipboard regarded as the cause of bad luck" (Jonah 1:v-xvi).
catapult (n.): 1570s, from Middle French catapulte and directly from Latin catapulta "war machine for throwing," from Greek katapeltes, from kata "against" (see cata-) + base of pallein "to toss, hurl" (see pulse (n.1)). As an airplane-launching device on an aircraft-carrier by 1927.
delirium (n.): 1590s, from Latin delirium "madness," from deliriare "be crazy, rave," literally "go off the furrow," a plowing metaphor, from phrase de lire, from de "off, away" (see de-) + lira "furrow, earth thrown up between two furrows," from PIE *leis- (1) "track, furrow" (see learn).
indomitable (adj.): 1630s, "that cannot be tamed or subdued," from Late Latin indomitabilis "untameable," from in- "not, opposite of, without" (see in- (1)) + *domitabilis, from Latin domitare, frequentative of domare "to tame" (see tame (adj.)). In reference to persons or personal qualities, "unyielding, persistent, resolute," by 1830. Related: Indomitably.
ineluctable (adj.): "not to be escaped by struggling," 1620s, from French inéluctable (15c.) or directly from Latin ineluctabilis "unavoidable, inevitable," from in- "not, opposite of" (see in- (1)) + eluctabilis "that may be escaped from," from eluctari "to struggle out of," from ex- "out" (see ex-) + luctari "to struggle" (see reluctance).
inept (adj.): c. 1600, "not fit or suitable, inapt," also "absurd, foolish," from French inepte "incapable" (14c.) or directly from Latin ineptus "unsuitable, improper, impertinent; absurd, awkward, silly, tactless," from in- "not, opposite of" (see in- (1)) + aptus "apt" (see apt). Related: Ineptly; ineptness.
inerrant (adj.): 1650s, in reference to "fixed" stars (as opposed to "wandering" planets), from Latin inerrantem (nominative inerrans) "not wandering, fixed (of stars)," from in- "not, opposite of" (see in- (1)) + errans, present participle of errare "to wander, stray, roam, rove" (see err). Meaning "unerring, free from error" is from 1785.
inevitable (adj.): "unavoidable," mid-15c., from Latin inevitabilis "unavoidable," from in- "not, opposite of" (see in- (1)) + evitabilis "avoidable," from evitare "to avoid," from ex- "out" (see ex-) + vitare "shun," originally "go out of the way." As a noun from 1850. Related: Inevitableness.
inexorable (adj.): "unyielding, unrelenting," 1550s, from Middle French inexorable and directly from Latin inexorabilis "that cannot be moved by entreaty, unyielding," from in- "not, opposite of" (see in- (1)) + exorabilis "able to be entreated," from exorare "to prevail upon," from ex- "out" (see ex-) + orare "pray" (see orator). Related: Inexorably; inexorability.
infallible (adj.): "exempt from error in judgment, knowledge, or opinion," early 15c., from Medieval Latin infallibilis, from in- "not, opposite of" (see in- (1)) + Late Latin fallibilis (see fallible). In reference to Popes, attested from 1870, hence infallibilism, the doctrine of this; infallibilist. Related: Infallibly.
informal (adj.): mid-15c., "lacking form; not in accordance with the rules of formal logic," from in- (1) "not, opposite of" + formal (adj.). Meaning "irregular, unofficial, not according to rule or custom" is from c. 1600. Sense of "done without ceremony" is from 1828. Related: Informally.
infrequent (adj.): 1530s, "little used" (now obsolete); 1610s, "not occurring often," from Latin infrequentem (nominative infrequens) "occurring seldom, unusual; not crowded, absent," from in- "not" (see in- (1)) + frequens "repeated, regular, constant, often" (see frequent). Related: Infrequently.