- inductive (adj.)
- early 15c., from Old French inductif or directly from Late Latin inductivus, from induct-, past participle stem of inducere (see induce). As a term in logic, from 1764.
- inductor (n.)
- 1650s, from Latin inductor, agent noun from past participle stem of inducere (see induce). Electromagnetic sense begins in 1837.
- indulge (v.)
- 1630s, "to grant as a favor;" 1650s, of both persons and desires, "to treat with unearned favor;" a back-formation from indulgence, or else from Latin indulgere "to be complaisant." Related: Indulged; indulging.
- indulgence (n.)
- mid-14c., "freeing from temporal punishment for sin," from Old French indulgence or directly from Latin indulgentia "complaisance, fondness, remission," from indulgentem (nominative indulgens) "indulgent, kind, tender, fond," present participle of indulgere "be kind, yield," of unknown origin; perhaps from in- "in" + derivative of PIE root *dlegh- "to engage oneself."
Sense of "gratification of another's desire or humor" is attested from late 14c. That of "yielding to one's inclinations" (technically self-indulgence) is from 1640s. In British history, Indulgence also refers to grants of certain liberties to Nonconformists under Charles II and James II, as special favors rather than legal rights; specifically the Declarations of Indulgence of 1672, 1687, and 1688 in England and 1669, 1672, and 1687 in Scotland. - indulgent (adj.)
- c.1500, from Latin indulgentem (nominative indulgens), present participle of indulgere (see indulgence). Related: Indulgently.
- indurate (v.)
- 1530s, from Latin induratus, past participle of indurare "to make hard, harden" (see endure). Related: Indurated.
- induration (n.)
- late 14c., from Old French induracion "hardness, obstinacy" (14c.) or directly from Medieval Latin indurationem (nominative induratio) "hardness (especially of the heart)," noun of action from indurare (see endure).
- Indus
- river in Asia, from Sanskrit sindhu "river." The southern constellation, created 1603 by Bayer, represents "an Indian," not the river.
- industrial (adj.)
- 1774, from French industriel, from Medieval Latin industrialis, from Latin industria (see industry). Earlier the word had been used in English in a sense "resulting from labor" (1580s); the modern use is considered a reborrowing. Meaning "suitable for industrial use" is from 1904. As a style of dance music, attested from 1988. Industrial revolution was in use by 1840 to refer to recent developments and changes in England and elsewhere.
- industrialisation (n.)
- chiefly British English spelling of industrialization (q.v.); for spelling, see -ize.
- industrialism (n.)
- 1831, from industrial + -ism. Cf. French industrialisme (Saint-Simon, 1823).
- industrialist (n.)
- 1846, from industrial + -ist. Cf. French industrialiste (Saint-Simon, 1823). Earlier "one who makes a living by productive industry" (1837).
- industrialization (n.)
- 1883, from industrialize + -ation.
- industrialize (v.)
- 1852, from industrial + -ize, or else from French industrialiser (1842), from Medieval Latin industrialis. Related: Industrialized; industrializing.
- industrious (adj.)
- "characterized by energy, effort, and attention," 1520s (implied in industriously), from Middle French industrieux and directly from Late Latin industriosus, from Latin industria (see industry). Retains the etymological sense. Related: Industriousness.
- industry (n.)
- late 15c., "cleverness, skill," from Old French industrie "activity; aptitude" (14c.) or directly from Latin industria "diligence, activity, zeal," fem. of industrius "industrious, diligent," used as a noun, from early Latin indostruus "diligent," from indu "in, within" + stem of struere "to build" (see structure (n.)). Sense of "diligence, effort" is from 1530s; meaning "trade or manufacture" first recorded 1560s; that of "systematic work" is 1610s.
- indwelling (n.)
- "act of residing," late 14c. (Wyclif's translation of Latin inhabitatio), present participle of obsolete indwell, from in (adv.) + dwell (v.). He also used indweller for Latin inhabitans.
- inebriate (v.)
- late 15c., from Latin inebriatus, past participle of inebriare "to make drunk," from in- "in" (see in- (2)) + ebriare "make drunk," from ebrius "drunk," of unknown origin. Related: Inebriated; inebriating. Also inebriacy; inebriant (n. and adj.); inebriety; and inebrious.
- inebriated (adj.)
- "drunken," c.1600, past participle adjective from inebriate.
- inebriation (n.)
- 1520s, from Late Latin inebriationem (nominative inebriatio), noun of action from past participle stem of inebriare (see inebriate).
- inedible (adj.)
- "unfit to eat," 1822, from in- (1) "not, opposite of" + edible. Related: Inedibly; inedibility.
- ineducable (adj.)
- 1884, from in- (1) "not" + educable. Related: Ineducability.
- ineffability (n.)
- 1620s; see ineffable + -ity.
- ineffable (adj.)
- late 14c., from Old French ineffable (14c.) or directly from Latin ineffabilis "unutterable," from in- "not, opposite of" (see in- (1)) + effabilis "speakable," from effari "utter," from ex- "out" (see ex-) + fari "speak" (see fame (n.)). Plural noun ineffables was, for a time, a jocular euphemism for "trousers" (1823). Related: Ineffably.
- ineffective (adj.)
- 1650s, from in- (1) "not, opposite of" + effective. Related: Ineffectively; ineffectiveness.
- ineffectual (adj.)
- early 15c., from in- (1) "not, opposite of" + effectual. Related: Ineffectually; ineffectuality.
- inefficacious (adj.)
- 1650s, from in- (1) "not, opposite of" + efficacious. Related: Inefficaciously; inefficaciousness (1640s).
- inefficacy (n.)
- "want of force or virtue to produce the desired effect," 1610s, from Late Latin inefficacia, from inefficacem (nominative inefficax), from in- "not, opposite of" (see in- (1)) + efficax (see efficacy).
- inefficient (adj.)
- 1750, "not producing the desired effect," from in- (1) "not, opposite of" + efficient. Related: Inefficiency (1749); inefficiently.
- inelastic (adj.)
- 1748, from in- (1) "not, opposite of" + elastic. Figurative use attested by 1867.
- inelegant (adj.)
- c.1500, from French inélégant (15c.), from Latin inelegantem (nominative inelegans) "not choice, without taste, without judgment," from in- "not" (see in- (1)) + elegans (see elegant). Related: Inelegantly; inelegance.
- ineligible (adj.)
- 1770, from in- (1) "not, opposite of" + eligible.
- ineluctable (adj.)
- "not to be escaped by struggling," 1620s, from Latin ineluctabilis "unavoidable, inevitable," from in- "not, opposite of" (see in- (1)) + eluctari "to struggle out of," from ex- "out" (see ex-) + luctari "to struggle."
- inept (adj.)
- c.1600, from Old French inepte (14c.) or directly from Latin ineptus "unsuitable, improper, absurd, awkward, silly, tactless," from in- "not, opposite of" (see in- (1)) + aptus "apt" (see apt). Related: Ineptly; ineptness.
- ineptitude (n.)
- 1610s, from French ineptitude, from Latin ineptitudo, noun of quality from ineptus "unsuitable, absurd" (see inept).
- inequable (adj.)
- 1717, from Latin inaequabilis "uneven," from in- "not" (see in- (1)) + aequabilis (see equable).
- inequality (n.)
- early 15c., "difference of rank or dignity," from Old French inequalité (14c.) and directly from Medieval Latin inaequalitas, from Latin inaequalis "unequal," from in- "not, opposite of" (see in- (1)) + aequalis "equal" (see equal).
- inequitable (adj.)
- 1660s, from in- (1) "not, opposite of" + equitable. Related: Inequitably.
- inequity (n.)
- 1550s, from in- (1) "not, opposite of" + equity. Formed from the same elements as iniquity, but natively. Related: Inequities.
- ineradicable (adj.)
- 1794, from in- (1) "not, opposite of" + eradicable (see eradicate). Related: Ineradicably.
- inerrancy (n.)
- 1818, from inerrant + -cy.
- inerrant (adj.)
- 1650s, in reference to "fixed" stars (as opposed to "wandering" planets), from Latin inerrantem (nominative inerrans) "not wandering," from in- "not, opposite of" (see in- (1)) + errans, present participle of errare "to err" (see err).
- inert (adj.)
- 1640s, from French inerte (16c.) or directly from Latin inertem (nominative iners) "unskilled, inactive, helpless, sluggish, worthless," from in- "without" + ars (genitive artis) "skill" (see art (n.)). Originally of matter; specifically of gases from 1885. Of persons or creatures, from 1774.
- inertia (n.)
- 1713, introduced as a term in physics 17c. by German astronomer and physician Johann Kepler (1571-1630), from Latin inertia "unskillfulness, idleness," from iners (genitive inertis) "unskilled, inactive;" see inert. Used in Modern Latin by Newton (1687). Sense of "apathy" first recorded 1822.
- inertial (adj.)
- 1737, from inertia + -al (1).
- inertness (n.)
- 1660s, from inert + -ness.
- inescapable (adj.)
- 1792, from in- (1) "not, opposite of" + escapable (see escape). Related: Inescapably.
- inestimable (adj.)
- late 14c., "beyond estimation," from Old French inestimable (14c.) or directly from Latin inaestimabilis, from in- "not, opposite of" (see in- (1)) + aestimabilis (see estimable). Meaning "too precious to set a value on, priceless" is attested by 1570s. Related: Inestimably.
- inevitability (n.)
- 1640s, from inevitable + -ity.
- inevitable (adj.)
- 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."