Online Etymology Dictionary

increase (n.): late 14c., "action of increasing; results of an increasing," from increase (v.) or from verbs formed from the noun in Old French or Anglo-French. The stress shifted from 18c. to distinguish it from the verb.
incremental (adj.): 1715, from increment + -al (1). Related: Incrementally.
increpation (n.): "a chiding, a rebuking, censure," c. 1500, from Late Latin increpationem (nominative increpatio), noun of action from past participle stem of Latin increpare "to make noise at, scold, nag, upbraid," from in- "in" (see in- (2)) + crepare "to creak" (see raven (n.)).
incrimination (n.): 1650s, noun of action from Medieval Latin incriminare "to incriminate, accuse," from in- "in" (see in- (2)) + criminare "to accuse of a crime," from crimen (genitive criminis) "crime" (see crime).
inculcation (n.): 1550s, from inculcate (v.), or else Late Latin inculcationem (nominative inculcatio), noun of action from past participle stem of inculcare "to force upon; stamp in."
inculpation (n.): "incrimination," 1798, noun of action from inculpate (v.). Perhaps from or modeled on French inculpation (18c.).
inconveniency (n.): early 15c., "calamity, injury, harmful consequence," also "danger" (now obsolete), from Late Latin inconvenientia (see inconvenience (n.)). Meaning "trouble, disadvantage, quality of being inconvenient" is from 1550s.
incorruptibility (n.): mid-15c., from Late Latin incorruptibilitas, from incorruptibilis (see incorruptible).
incumbent (adj.): 1560s, in relation to duties or obligations, from Medieval Latin incumbentem (nominative incumbens), present participle of incumbere (see incumbent (n.)). The literal, physical sense "lying or resting on something" is rare in English and first attested 1620s.
indefinability (n.): 1814, from indefinable + -ity.
indefatigability (n.): 1630s, from indefatigable + -ity. Indefatigableness is from 1650s; indefatigation from 1640s.
indemnification (n.): 1732, "action of compensating for loss or damage," noun of action from indemnify.
indeterminacy (n.): 1640s, see indeterminate + -acy.
indeterminable (adj.): late 15c., from Late Latin indeterminabilis "that cannot be defined," from in- "not" (see in- (1)) + determinabilis "that can be defined," from determinare "to enclose, bound, set limits to" (see determine). Related: Indeterminably.
Indic (adj.): "pertaining to India or its inhabitants," 1877, from Latin Indicus "of India," or Greek Indikos "of India;" see India. Especially in reference to the Indo-European languages of India, living and dead.
indices (n.): according to OED, the plural form of index preferable in scientific and mathematical senses of that word.
index (v.): "compile an index," 1720, from index (n.). Related: Indexed; indexing.
indexation (n.): 1960, in reference to rates of wages, prices, etc. pegged to a specified index of economic activity, noun of action from index (v.).
indestructibility (n.): 1670s, from indestructible + -ity.
indirection (n.): "irregular means, deceitful action," 1590s, from indirect + -ion.
indispensability (n.): 1640s, from indispensable + -ity.
indissolubility (n.): 1670s, from indissoluble + -ity.
indiscriminately (adv.): 1650s, from indiscriminate + -ly (2).
individualize (v.): 1630s, "to make individual, stamp with individual character;" 1650s, "to point out individually, to note separately as individuals;" see individual + -ize. Related: Individualized; individualizing.
indivisibility (n.): 1640s, from indivisible + -ity. Perhaps modeled on French indivisibilité.
individuate (v.): 1610s, from Medieval Latin individuatus, past participle of individuare "make individual," from Latin individuus "individual" (see individual (adj.)). Perhaps modeled on obsolete French individuer. Related: Individuated; individuating.
indoctrination (n.): 1640s, "instruction," noun of action from indoctrinate. In reference to imbuing with opinions or ideology, from 1865.
indrawn (adj.): also in-drawn, 1751, from in (adv.) + past tense of draw (v.). Middle English had indraw "bring about, cause" (late 14c.), "pull inward" (early 15c.). Also compare indraft "inward flow, a drawing in" (1590s). The modern verb indraw (1871) is rare and might be a back-formation.
inductee (n.): 1941, American English, from induct + -ee.
ineducable (adj.): "not capable of being instructed," 1858, from in- (1) "not" + educable. Related: Ineducably; ineducability (1871).
ineffability (n.): "unspeakableness," 1620s, from ineffable + -ity.
inebriation (n.): 1520s, from Late Latin inebriationem (nominative inebriatio) "drunkenness," noun of action from past participle stem of inebriare "make drunk" (see inebriate).
inequable (adj.): "not uniform, changeable," 1716, from Latin inaequabilis "unequal," from in- "not" (see in- (1)) + aequabilis "similar, equal; constant, not varying" (see equable). Related: Inequability (1580s).
inelegant (adj.): c. 1500, from Middle French inélégant (15c.), from Latin inelegantem (nominative inelegans) "not elegant, not choice," also "without taste, without judgment," from in- "not" (see in- (1)) + elegans (see elegant). Related: Inelegantly.
inerrancy (n.): 1788, from inerrant + -cy.
I.R.A. (2): also IRA, initialism (acronym) for individual retirement account, attested from 1974.
I.R.A. (1): also IRA, 1921, initialism (acronym) for Irish Republican Army, the full name of which attested from 1919.
ISBN: 1969, acronym for International Standard Book Number.
iatro-: word-forming element meaning "a physician; medicine; healing," from Greek iatros "healer, physician" (see -iatric).
iceman (n.): "dealer in ice," 1844, from ice (n.) + man (n.).
ice-box (n.): also icebox, 1839, "an ice chest," later "the small compartment in a refrigerator containing the ice," from ice (n.) + box (n.).
Ice-Capade (n.): 1941, originally a film title, from ice (n.) + a punning play on escapade.
ice-water (n.): 1722, from ice (n.) + water (n.1).
idealization (n.): 1796; see idealize + -ation. Perhaps via French idéalisation.
identifier (n.): "thing that identifies," 1870, agent noun from identify.
imperialistic (adj.): 1872, from imperialist + -ic.
impersonation (n.): 1800, "personification;" 1825 as "an acting of a part or character;" noun of action from impersonate (v.).
impetuosity (n.): early 15c., "violent movement, rushing," from Old French impetuosité (13c.) and directly from Medieval Latin impetuositatem (nominative impetuositas), from Late Latin impetuosus "impetuous, violent" (see impetuous).
impingement (n.): 1670s, "act of impinging;" see impinge + -ment.
implantation (n.): 1570s, "manner of being implanted," from French implantation, noun of action from implanter "to insert, engraft" (see implant (v.)). From c. 1600 as "act of implanting;" in embryology from 1902.