intergenerational (adj.) Look up intergenerational at Dictionary.com
1964, from inter- + generation + -al (1).
interglacial (adj.) Look up interglacial at Dictionary.com
1867 in reference to warm spells between ice ages, from German, coined 1865 by Swiss naturalist Oswald Heer (1809-1883); see inter- "between" + glacial. The word was used earlier in reference to situations between glaciers or ice caps (1835).
interim (n.) Look up interim at Dictionary.com
"time intervening," 1560s, from Latin interim (adv.) "in the meantime, meanwhile," originally "in the midst of that," from inter- "between" (see inter-) + im, ancient adverb from stem of pronoun is "this, that." As an adjective from c. 1600.
interior (adj.) Look up interior at Dictionary.com
late 15c., from Latin interior "inner, interior, middle," comparative adjective of inter "within" (see inter-). Specific meaning "away from the coast, of the interior parts of a country" is from 1777. Interior decoration first attested 1769; interior decorator is from 1830. Interior design from 1927.
interior (n.) Look up interior at Dictionary.com
"part of a country distant from the coast," 1796, from interior (adj.); meaning "internal part, inside" is from 1828. Meaning "internal affairs of a country or state" (as in U.S. Department of the Interior) is from 1826. The Latin adjective also was used as a noun.
interiority (n.) Look up interiority at Dictionary.com
1701, from interior + -ity.
interjacent (adj.) Look up interjacent at Dictionary.com
1590s, from Latin interiacentem (nominative interiacens) "lying between," present participle of interiacere "to lie between," from inter- (see inter-) + iacere "to throw; to set, establish" (see jet (v.)). Related: Interjacency.
interject (v.) Look up interject at Dictionary.com
1570s, back-formation from interjection or else from Latin interiectus, past participle of intericere "to throw between, insert, interject." Related: Interjected; interjecting.
interjection (n.) Look up interjection at Dictionary.com
early 15c., "an interjected or exclamatory word," from Middle French interjection (Old French interjeccion, 13c.), from Latin interiectionem (nominative interiectio) "a throwing or placing between," also in grammar and rhetoric, noun of action from past participle stem of intericere "to throw between, set between," from inter- "between" (see inter-) + -icere, comb. form of iacere "to throw" (see jet (v.)). Related: Interjectional.
interlace (v.) Look up interlace at Dictionary.com
formerly also enterlace, late 14c. (trans.), "unite by crossing the laces," thus, "entangle, bind together," from Old French entrelacier (12c.), from entre- (see entre-) "between" + lacier "to tie, entangle," from laz (see lace (n.)).

Intransitive sense from 1590s. Television sense is from 1927. Related: Interlaced; interlacing; interlacement. The noun is 1904, from the verb.
interlanguage (n.) Look up interlanguage at Dictionary.com
"artificial or auxilliary language," 1927, from inter- + language.
interlard (v.) Look up interlard at Dictionary.com
early 15c., "to mix with alternate layers of fat" (before cooking), from Old French entrelarder (12c.), from entre- "between" (see inter-) + larder "to lard," from Old French lard "bacon fat" (see lard (n.)). Figurative sense of "diversify with something intermixed" first recorded 1560s. Related: Interlarded; interlarding; interlardment.
interleaf (n.) Look up interleaf at Dictionary.com
"extra page in a book," usually left blank and for taking notes, 1741, from inter- "between" + leaf (n.).
interleague (adj.) Look up interleague at Dictionary.com
also inter-league, by 1917 in a U.S. baseball sense, from inter- "between" + league (n.). Earlier (1580s) as a verb, "to combine in a league."
interline (v.) Look up interline at Dictionary.com
c. 1400, "make corrections or insertions between the lines of (a document)," from inter- "between" + line; perhaps modeled on Old French entreligniere or Medieval Latin interlineare "write between lines." Related: Interlined; interlining; interlineation.
interlinear (adj.) Look up interlinear at Dictionary.com
late 14c., "situated between the lines," from Medieval Latin interlinearis "that which is between the lines," from inter- (see inter-) "between" + Latin linearis (see linear). Meaning "having interpolated lines" is from 1620s. Related: Interlineary.
interlingual (adj.) Look up interlingual at Dictionary.com
"between or relating to two languages," 1854, from inter- "between" + lingual. Related: Interlingually.
interlock (v.) Look up interlock at Dictionary.com
1630s, "to be locked together," from inter- "between" + lock (v.). Related: Interlocked; interlocking. As a noun, attested by 1856.
interlocution (n.) Look up interlocution at Dictionary.com
"interchange of speech, dialogue, action of talking and replying," 1530s, from Latin interlocutionem (nominative interlocutio) "a speaking between, interlocution," noun of action from past participle stem of interloqui "to speak between; to interrupt" (see interlocutor).
interlocutor (n.) Look up interlocutor at Dictionary.com
1510s, "one who speaks in a dialogue or conversation," agent noun from Latin interlocut-, past participle stem of interloqui "speak between; interrupt," from inter- "between" (see inter-) + loqui "to speak" (see locution).

In minstrel shows, the name of a straight-man character (1870) who was the questioner of the end men. Related: Interlocutory. Fem. forms include interlocutress (1858), interlocutrix (1846), interlocutrice (1848).
interlope (v.) Look up interlope at Dictionary.com
"intrude where one has no business," especially with a view to gain the advantage or profits of another (as a trader without a proper license), early 17c., probably a back-formation from interloper (q.v.). Related: Interloped; interloping.
interloper (n.) Look up interloper at Dictionary.com
1590s, enterloper, "unauthorized trader trespassing on privileges of chartered companies," probably a hybrid from inter- "between" + -loper (from landloper "vagabond, adventurer," also, according to Johnson, "a term of reproach used by seamen of those who pass their lives on shore"); perhaps from a dialectal form of leap, or from Middle Dutch loper "runner, rover," from lopen "to run," from Proto-Germanic *hlaupan "to leap" (see leap (v.)).

OED says Dutch enterlooper "a coasting vessel; a smuggler" is later than the English word and said by Dutch sources to be from English. General sense of "self-interested intruder" is from 1630s.
interlude (n.) Look up interlude at Dictionary.com
formerly also enterlude, c. 1300, from Old French entrelude and directly from Medieval Latin interludium "an interlude," from Latin inter "between" (see inter-) + ludus "a play" (see ludicrous). Originally the term for farcical episodes drawn from real life introduced between acts of long mystery plays. In 17c.-18c. it meant "popular stage play;" transferred (non-dramatic) sense of "interval in the course of some action" is from 1751. Related: Interludial.
intermarriage (n.) Look up intermarriage at Dictionary.com
1570s, "act or fact of marrying" (now mostly restricted to legal use), from inter- + marriage. Meaning "marriage between members of different classes, tribes, etc." is from c. 1600.
intermarry (v.) Look up intermarry at Dictionary.com
1570s, "to marry one another," from inter- + marry (v.). Meaning "to marry across families, castes, tribes, etc." is from 1610s. Related: Intermarried; intermarrying.
intermeddle (v.) Look up intermeddle at Dictionary.com
late 14c., entremedlen, "to mix together, blend," from Anglo-French entremedler, Old French entremesler; from inter- + Anglo-French medler (see meddle (v.)). From early 15c. as "involve oneself in what is not one's business."
intermediacy (n.) Look up intermediacy at Dictionary.com
1713, from intermediate + -cy. Intermediateness is from 1826.
intermediary (adj.) Look up intermediary at Dictionary.com
1757, "situated between two things;" 1818 as "serving as a mediator;" from French intermédiaire (17c.), from Latin intermedius "that which is between" (see intermediate). As a noun, "one who acts between others" from 1791 (Medieval Latin intermedium also was used as a noun). An earlier adjective was intermedial (1590s).
Intermediary, n., is, even with concrete sense of go-between or middleman or mediator, a word that should be viewed with suspicion & resorted to only when it is clear that every more ordinary word comes short of the need. [Fowler]
intermediate (adj.) Look up intermediate at Dictionary.com
"being or occurring between" (two things), early 15c., from Medieval Latin intermediatus "lying between," from Latin intermedius "that which is between," from inter- "between" (see inter-) + medius "in the middle" (see medial (adj.)).
intermediate (v.) Look up intermediate at Dictionary.com
c. 1600, "to interfere;" 1620s, "to mediate," from inter- "between" + mediate (v.). Related: Intermediated; intermediating.
intermediation (n.) Look up intermediation at Dictionary.com
c. 1600, noun of action from intermediate (v.).
interment (n.) Look up interment at Dictionary.com
early 14c., from Old French enterrement "burial, interment," from enterrer (see inter (v.)).
intermesh (v.) Look up intermesh at Dictionary.com
1863, in reference to gears, from inter- "between" + mesh (v.). Related: Intermeshed; intermeshing.
intermezzo (n.) Look up intermezzo at Dictionary.com
1782, from Italian intermezzo "short dramatic performance (usually light and pleasing) between the acts of a play or opera," literally "that which is between," from Latin intermedius (see intermediate (adj.)).
intermigration (n.) Look up intermigration at Dictionary.com
"reciprocal migration," 1670s, from inter- "between" + migration.
interminable (adj.) Look up interminable at Dictionary.com
late 14c., from Old French interminable (14c.) or directly from Late Latin interminabilis "endless," from in- "not" (see in- (1)) + terminabilis, from terminare "to limit, set bounds, end" (see terminus (adj.)). Related: Interminably.
interminate (adj.) Look up interminate at Dictionary.com
1530s, from Latin interminatus "unbounded, endless," from in- "not" (see in- (1)) + terminalis "pertaining to a boundary or end, final," from terminus "end, boundary line" (see terminus).
intermingle (v.) Look up intermingle at Dictionary.com
late 15c. (trans.), from inter- "between" + mingle (v.). Intransitive sense from 1620s. Related: Intermingled; intermingling.
interministerial (adj.) Look up interministerial at Dictionary.com
1917, in reference to branches of government, from inter- "between" + ministerial.
intermission (n.) Look up intermission at Dictionary.com
early 15c., "fact of intermitting, temporary pause," from Latin intermissionem (nominative intermissio) "a breaking off, discontinuance, interruption," noun of action from past participle stem of intermittere "to leave off, leave an interval," from inter- "between" (see inter-) + mittere "let go, send" (see mission). Meaning "lapse of time between events" is from 1560s; specifically of performances (originally plays, later movies, etc.) from 1854.
Intermission is used in U.S. for what we call an interval (in a musical or dramatic performance). Under the influence of LOVE OF THE LONG WORD, it is beginning to infiltrate here and should be repelled; our own word does very well. [H.W. Fowler, "Modern English Usage," 1926]
intermissive (adj.) Look up intermissive at Dictionary.com
"not continuous," 1580s, from Latin intermiss-, past participle stem of intermittere "leave off, leave an interval" (see intermit).
intermit (v.) Look up intermit at Dictionary.com
1540s, "to interrupt" (obsolete); 1570s as "to discontinue for a time, suspend" (trans.) and "cease for a time" (intrans.), from Latin intermittere "to leave off, leave an interval, omit, suspend, interrupt, neglect," from inter- "between" (see inter-) + mittere "to send" (see mission). Related: Intermitted; intermitting.
intermittence (n.) Look up intermittence at Dictionary.com
1796, from intermittent + -ence. Perhaps from French. Intermittency is from 1660s.
intermittent (adj.) Look up intermittent at Dictionary.com
c. 1600, from Latin intermittentem (nominative intermittens), present participle of intermittere "to leave off, cease, pause" (see intermission). Related: Intermittently.
intermitting (adj.) Look up intermitting at Dictionary.com
"stopping at intervals," 1620s, present-participle adjective from intermit (v.). Related: Intermittingly.
intermix (v.) Look up intermix at Dictionary.com
1550s (implied in intermixed), from inter- "between" + mix (v.). Originally transitive; intransitive sense is from 1722. Related: Intermixt; intermixing.
intermixture (n.) Look up intermixture at Dictionary.com
1580s, "that which is mixed;" 1590s, "action of intermixing;" see inter- + mixture (n.).
intermodal (adj.) Look up intermodal at Dictionary.com
1963, from inter- "between" + modal (adj.).
intermural (adj.) Look up intermural at Dictionary.com
1650s, from Latin intermuralis "situated between walls," from inter- "between" (see inter-) + murus (genitive muralis) "wall" (see mural).
intern (v.1) Look up intern at Dictionary.com
1866, "to confine within set limits," from French interner "send to the interior, confine," from Middle French interne "inner, internal" (14c.), from Latin internus "within, internal" (see internal; also compare intern (n.)).