impervious (adj.) Look up impervious at
1640s, from Latin impervius "that cannot be passed through," from assimilated form of in- "not, opposite of" (see in- (1)) + pervius "letting things through," from per "through" + via "road." Related: Imperviously; imperviousness.
impetigo (n.) Look up impetigo at
pustular disease of the skin, late 14c., from Latin impetigo "skin eruption," from impetere "to attack√Ę" (see impetus). Related: Impetiginous.
impetuosity (n.) Look up impetuosity at
early 15c., "violent movement, rushing," from Old French impetuosité (13c.), from Medieval Latin impetuositatem (nominative impetuositas), from Late Latin impetuosus (see impetuous).
impetuous (adj.) Look up impetuous at
late 14c., "hot-tempered, fierce," from Old French impetuos (13c.) and directly from Late Latin impetuosus "impetuous, violent," from Latin impetus "attack" (see impetus). Related: Impetuously; impetuousness.
impetus (n.) Look up impetus at
early 15c., impetous "rapid movement, rush;" 1640s, with modern spelling, "force with which a body moves, driving force," from Latin impetus "attack, assault, onset, impulse, violence, vigor, force, passion," related to impetere "to attack," from assimilated form of in- "into, in, on, upon" (see in- (2)) + petere "aim for, rush at" (see petition (n.)).
impiety (n.) Look up impiety at
mid-14c., from Old French impieté (12c.), from Latin impietatem (nominative impietas) "irreverence, ungodliness; disloyalty, treason," noun of quality from impius (see impious).
impinge (v.) Look up impinge at
1530s, "fasten or fix forcibly," from Latin impingere "drive into, strike against," from assimilated form of in- "into, in, on, upon" (see in- (2)) + pangere "to fix, fasten" (see pact). Sense of "encroach, infringe" first recorded 1738. Related: Impinged; impinging.
impingement (n.) Look up impingement at
1670s; see impinge + -ment.
impious (adj.) Look up impious at
1590s, from Latin impius "without reverence, irreverent, wicked; undutiful, unpatriotic," from assimilated form of in- "not, opposite of" (see in- (1)) + pius (see pious). Related: Impiously; impiousness.
impish (adj.) Look up impish at
1650s, from imp + -ish. Related: Impishly; impishness.
implacability (n.) Look up implacability at
1530s, from Late Latin implacabilitas, from Latin implacabilis (see implacable).
implacable (adj.) Look up implacable at
early 15c., from Old French implacable, from Latin implacabilis "unappeasable," from assimilated form of in- "not, opposite of" (see in- (1)) + placabilis "easily appeased" (see placate). Related: Implacably.
implant (v.) Look up implant at
early 15c., from French implanter "to insert, engraft," from assimilated form of in- "into, in, on, upon" (see in- (2)) + planter "to plant" (see plant (n.)). Related: Implanted; implanting.
implant (n.) Look up implant at
1890 as "thing implanted;" 1941 as "action of implanting," from implant (v.). Related: Implants, by 1981 as short for breast implants (1976).
implantation (n.) Look up implantation at
1570s, from French implantation, noun of action from implanter (see implant (v.)).
implausibility (n.) Look up implausibility at
1630s; see implausible + -ity.
implausible (adj.) Look up implausible at
c. 1600, from assimilated form of in- "not, opposite of" (see in- (1)) + plausible. Related: Implausibly.
implement (n.) Look up implement at
mid-15c., from Late Latin implementem "a filling up" (as with provisions), from Latin implere "to fill," from assimilated form of in- "into, in, on, upon" (see in- (2)) + plere "to fill" (see pleio-). Sense of "tool" is 1530s, from notion of things provided to do work, that which "fills up" or "completes" a household (c. 1500).
implement (v.) Look up implement at
1806, originally chiefly in Scottish, where the noun was a legal term meaning "fulfillment," from implement (n.). It led to the wretched formation implementation, first recorded 1913. Related: Implemented.
implicate (v.) Look up implicate at
early 15c., "to convey in a fable;" c. 1600, "intertwine, wreathe," from Latin implicatus, past participle of implicare "to involve, entwine" (see implication). Meaning "involve a person in a crime, charge, etc.," is from 1797. Related: Implicated; implicating.
implication (n.) Look up implication at
early 15c., "action of entangling," from Latin implicationem (nominative implicatio) "interweaving, entanglement," from past participle stem of implicare "involve, entangle, connect closely," from assimilated form of in- "into, in, on, upon" (see in- (2)) + plicare "to fold" (see ply (v.1)). Meaning "something implied (but not expressed)" is from 1550s.
implications (n.) Look up implications at
see implication.
implicit Look up implicit at
1590s, from Middle French implicite and directly from Latin implicitus, later variant of implicatus, past participle of implicare (see implication).
implicitly (adv.) Look up implicitly at
c. 1600, from implicit + -ly (2).
implode (v.) Look up implode at
1870 (implied in imploded), back-formation from implosion. Related: Imploding.
implore (v.) Look up implore at
c. 1500, from Middle French implorer and directly from Latin implorare "call for help, beseech," originally "invoke with weeping," from assimilated form of in- "on, upon" (see in- (2)) + plorare "to weep, cry out." Related: Implored; imploring; imploringly.
implosion (n.) Look up implosion at
"a bursting inward," 1829, modeled on explosion, with assimilated form of in- "into, in, on, upon" (see in- (2)).
And to show how entire the neglect and confusion have been, they speak in the same breath of all these explosions, and of the explosion of a mixture of hydrogen and oxygen, the result of which, instead of being a gas or an enlargement of bulk, a positive quantity, is a negative one. It is a vacuum, in a popular sense, because the produce is water. The result is an implosion (to coin a word), not an explosion .... ["Gas-light," "Westminster Review," October 1829]
In early use often in reference to effect of deep sea pressures, or in phonetics. Figurative sense is by 1960.
imply (v.) Look up imply at
late 14c., "to enfold, enwrap, entangle" (the classical Latin sense), from Old French emplier, from Latin implicare "involve" (see implication). Meaning "to involve something unstated as a logical consequence" first recorded c. 1400; that of "to hint at" from 1580s. Related: Implied; implying. The distinction between imply and infer is in "What do you imply by that remark?" But, "What am I to infer from that remark?"
impolite (adj.) Look up impolite at
1610s, "unrefined, rough," from Latin impolitus "unpolished, rough, unrefined," from assimilated form of in- "not, opposite of" (see in- (1)) + politus "polished" (see polite). Sense of "discourteous, ill-mannered" is from 1739. Related: Impolitely; impoliteness.
impolitic (adj.) Look up impolitic at
"not according to good policy," c. 1600, from assimilated form of in- (1) "not, opposite of" + politic.
imponderable (adj.) Look up imponderable at
1794, "weightless," from assimilated form of in- (1) "not, opposite of" + ponderable (see ponder). Figurative use, "unthinkable," from 1814. Related: Imponderably. As a noun, by 1842.
import (v.) Look up import at
early 15c., "convey information, express, make known, signify," from Latin importare "bring in, convey," from assimilated form of in- "into, in" (see in- (2)) + portare "to carry" (see port (n.1)). Sense of "bring in goods from abroad" first recorded c. 1500. Related: Imported; importing.
import (n.) Look up import at
"consequence, importance," 1580s; sense of "that which is imported" is from 1680s; both from import (v.).
importance (n.) Look up importance at
c. 1500, from Middle French importance or directly from Medieval Latin importantia, from importantem (see important).
important (adj.) Look up important at
mid-15c., from Middle French important and directly from Medieval Latin importantem (nominative importans), present participle of importare "be significant in," from Latin importare "bring in" (see import). Related: Importantly.
importation (n.) Look up importation at
c. 1600; see import (v.) + -ation.
importunate (adj.) Look up importunate at
1520s, from importune + -ate, or else from Medieval Latin importunatus, past participle of importunari. Related: Importunately (mid-15c.).
importune (v.) Look up importune at
1520s, back-formation from importunity, or else from Middle French importuner, from Medieval Latin importunari "to make oneself troublesome," from Latin importunus "unfit, troublesome," originally "having no harbor" (i.e. "difficult to access"), from assimilated form of in- "not, opposite of" (see in- (1)) + portus "harbor" (see port (n.1)). Related: Importuned; importuning. As an adjective from early 15c.
importunity (n.) Look up importunity at
early 15c., "persistence, insistence; over-eagerness," from Middle French importunité (14c.), from Latin importunitatem (nominative importunitas) "unsuitableness; unmannerliness, incivility," from importunus "unfit, troublesome" (see importune).
impose (v.) Look up impose at
late 14c., "to lay (a crime, etc.) to the account of," from Old French imposer "put, place; impute, charge, accuse" (c. 1300), from assimilated form of in- "into, in" (see in- (2)) + poser "put, place" (see pose (v.1)). Sense of "to lay on as a burden" first recorded 1580s. Related: Imposed; imposing.
imposing (adj.) Look up imposing at
"that impresses by appearance or manner," 1786, from present participle of impose (v.). Related: Imposingly.
imposition (n.) Look up imposition at
late 14c., "the levying of taxes, a tax, duty, tribute," from Old French imposicion "tax, duty; a fixing" (early 14c.), from Latin impositionem (nominative impositio) "a laying on," from imponere "to place upon," from assimilated form of in- "into, in" (see in- (2)) + ponere "to put, place" (past participle positus; see position (n.)). Sense of "the act of putting (something) on (something else)" is from 1590s. Meaning "an act or instance of imposing" (on someone) first recorded 1630s (see impose).
impossibility (n.) Look up impossibility at
late 14c., "quality of being impossible," from impossible + -ity; perhaps from or modeled on French impossibilité. Meaning "an impossible thing or occurrence" is from c. 1500.
impossible (adj.) Look up impossible at
late 14c., from Old French impossible, from Latin impossibilis "not possible," from assimilated form of in- "not, opposite of" (see in- (1)) + possibilis (see possible). Related: Impossibly.
impost (n.) Look up impost at
"tax, duty," 1560s, from Middle French impost, from Medieval Latin impostum, from neuter of Latin impostus, contracted from impositus, past participle of imponere (see impostor).
impostor (n.) Look up impostor at
1580s, from Middle French imposteur (16c.), from Late Latin impostor, agent noun from impostus, collateral form of impositus, past participle of imponere "place upon, impose upon, deceive," from assimilated form of in- "into, in, on, upon" (see in- (2)) + ponere "to put place" (past participle positus; see position (n.)).
imposture (n.) Look up imposture at
"act of willfully deceiving others," 1530s, from Middle French imposture, from Late Latin impostura, from impostus (see impost).
impotence (n.) Look up impotence at
early 15c., "physical weakness," also "poverty," from Middle French impotence "weakness," from Latin impotentia "lack of control or power," from impotentem (nominative impotens); see impotent. In reference to a want of (male) sexual potency, from c. 1500. The figurative senses of the word in Latin were "violence, fury, unbridled passion." Related: Impotency.
impotent (adj.) Look up impotent at
late 14c., "physically weak, enfeebled, crippled," from Old French impotent "powerless, weak, incapable," from Latin imponentem (nominative impotens) "lacking control, powerless," from assimilated form of in- "not, opposite of" (see in- (1)) + ponentem (nominative potens) "potent" (see potent).

Meaning "having no power to accomplish anything" is from mid-15c.; that of "completely lacking in sexual power" (of males) is from mid-15c. Middle English also had a native term for this: Cunt-beaten (mid-15c.). The figurative sense in Latin was "without self-control, headstrong, violent." Related: Impotently.
impound (v.) Look up impound at
early 15c., "to shut up in a pen or pound," from assimilated form of in- "into, in" (see in- (2)) + pound (n.). Originally of cattle seized by law. Related: Impounded; impounding.