intensity (n.) Look up intensity at
formed in English 1660s from intense + -ity. Earlier was intenseness (1610s). Sense of "extreme depth of feeling" first recorded 1830.
intensive (adj.) Look up intensive at
mid-15c., from French intensif (14c.), from Latin intens-, past participle stem of intendere (see intend). As a noun, 1813, from the adjective. Alternative intensitive is a malformation. Intensive care attested from 1958. Related: Intensively.
intent (n.) Look up intent at
"purpose," early 13c., from Old French entente, from Latin intentus "a stretching out," in Late Latin "intention, attention," noun use of past participle of intendere "stretch out, lean toward, strain," literally "to stretch out" (see intend).
intent (adj.) Look up intent at
"very attentive," late 14c., from Latin intentus "attentive, eager, waiting, strained," past participle of intendere "to strain, stretch" (see intend). Related: Intently.
intention (n.) Look up intention at
mid-14c., from Old French entencion "stretching, intensity, will, thought" (12c.), from Latin intentionem (nominative intentio) "a stretching out, straining, exertion, effort; attention," noun of action from intendere "to turn one's attention," literally "to stretch out" (see intend).
intentional (adj.) Look up intentional at
1520s, from Medieval Latin intentionalis, from intentionem (see intention). Intentional fallacy recorded from 1946. Related: Intentionality.
intentionally (adv.) Look up intentionally at
"on purpose," 1660s; see intentional + -ly (2).
intentions (n.) Look up intentions at
"one's purposes with regard to courtship and marriage," by 1796; see intention.
intentive (adj.) Look up intentive at
late 13c., from Old French ententif, intentif (12c.), from Late Latin intentivus, from intent-, past participle stem of intendere (see intend).
inter (v.) Look up inter at
c. 1300, from Old French enterer (11c.), from Medieval Latin interrare "put in the earth, bury," from Latin in- "in" (see in- (2)) + terra "earth" (see terrain). Related: Interred; interring.
inter alia Look up inter alia at
Latin, literally "amongst other things." (Latin for "among other persons" is inter alios), from inter "among, between" (see inter-).
inter- Look up inter- at
Latin inter (prep., adv.) "among, between, betwixt, in the midst of," from PIE *enter "between, among" (cognates: Sanskrit antar, Old Persian antar "among, between," Greek entera (plural) "intestines," Old Irish eter, Old Welsh ithr "among, between," Gothic undar, Old English under "under"), a comparative of *en "in" (see in). Also in certain Latin phrases in English, such as inter alia "among other things." A living prefix in English from 15c. Spelled entre- in French, most words borrowed into English in that form were re-spelled 16c. to conform with Latin except entertain, enterprise.
inter-war (adj.) Look up inter-war at
1939, in reference to the period between the world wars, from inter- + war (n.).
interact (v.) Look up interact at
"to act on each other," 1805, from inter- + act (v.). Related: Interacted; interacting.
interaction (n.) Look up interaction at
1812, from inter- + action.
interactive (adj.) Look up interactive at
1832, from interact, probably on model of active. Related: Interactivity.
interbreed (v.) Look up interbreed at
1859, from inter- + breed. Related: Interbred; interbreeding.
intercalary (adj.) Look up intercalary at
1610s, from Latin intercalarius, from intercalare (see intercalate).
intercalate (v.) Look up intercalate at
"to insert a day into the calendar," 1610s, from Latin intercalatus, past participle of intercalare "to proclaim the insertion of an intercalary day," from inter- "between" (see inter-) + calare (see calendar). Related: Intercalated; intercalating.
intercalation (n.) Look up intercalation at
1570s, from Latin intercalationem (nominative intercalatio) "insertion of an intercalary day," noun of action from past participle stem of intercalare (see intercalate).
intercede (v.) Look up intercede at
1570s, a back-formation from intercession, or else from Latin intercedere "intervene, come between, be between," from inter- "between" (see inter-) + cedere "go" (see cede). Related: Interceded; interceding.
intercept (v.) Look up intercept at
c. 1400, from Latin interceptus, past participle of intercipere "take or seize between, to seize in passing," from inter- "between" (see inter-) + -cipere, comb. form of capere "to take, catch" (see capable). Related: Intercepted; intercepting.
interception (n.) Look up interception at
early 15c., "action of intercepting" (the flow of a bodily fluid), from Latin interceptionem (nominative interceptio) "a seizing, taking away," noun of action from intercipere (see intercept). Specific football/rugby sense is attested by 1906. Meaning "action of closing in on and destroying an enemy aircraft, etc." is recorded from 1941.
interceptor (n.) Look up interceptor at
1590s, from Latin interceptor, agent noun from intercipere (see intercept). As a type of fast fighter aircraft, from 1930.
intercession (n.) Look up intercession at
early 15c., "act of interceding," from Latin intercessionem (nominative intercessio) "a going between," noun of action from past participle stem of intercedere (see intercede). The modern sense was not in classical Latin.
intercessor (n.) Look up intercessor at
late 15c., from Latin intercessor "one who intervenes," agent noun from intercedere (see intercede). Related: Intercessory.
interchange (v.) Look up interchange at
late 14c., from Old French entrechangier, from entre- (see inter-) + changier "to change" (see change (v.)). Related: Interchanged; interchanging.
interchange (n.) Look up interchange at
1540s, "act of exchange, from Old French entrechange, from entrechangier (see interchange (v.)). In reference to a type of road junction, 1944.
interchangeable (adj.) Look up interchangeable at
late 14c. (implied in interchangeably), from inter- + changeable. Related: Interchangeability.
intercoastal (adj.) Look up intercoastal at
"within the coasts," 1927, from inter- + coastal.
intercom (n.) Look up intercom at
1940, colloquial shortening of intercommunication (mid-15c., "discussion, conference;" see inter- + communication), which is attested from 1911 in reference to systems of linked telephones.
interconnect (v.) Look up interconnect at
1863, from inter- + connect. Related: Interconnected; interconnecting; interconnectedness; interconnection.
intercontinental (adj.) Look up intercontinental at
1825, American English, from inter- + continental. Of missiles, from 1956.
intercostal (adj.) Look up intercostal at
"between the ribs," 1590s; see inter- + costal.
intercourse (n.) Look up intercourse at
mid-15c., "communication to and fro," from Old French entrecours "exchange, commerce," from Late Latin intercursus "a running between, intervention," from intercursus, past participle of intercurrere "to run between," from Latin inter- "between" (see inter-) + currere "to run" (see current (adj.)). Meaning "sexual relations" first recorded 1798, from earlier sense "social contact and relations" (1540s).
intercrural (adj.) Look up intercrural at
"between the thighs," or in madicine, "between leg-like structures," 1690s, from inter- + Latin crus "shin, shinbone leg; supports of a bridge."
interdepartmental (adj.) Look up interdepartmental at
also inter-departmental, 1861, from inter- + departmental.
interdependence (n.) Look up interdependence at
1822, from inter- + dependence.
interdependency (n.) Look up interdependency at
1838, from interdependent + -cy.
interdependent (adj.) Look up interdependent at
1817, from inter- + dependent. Related: Interdependently.
interdict (v.) Look up interdict at
late 13c., from Old French entredit, past participle of entredire "forbid by decree," from Latin interdicere "interpose by speech, prohibit," from inter- "between" (see inter-) + dicere "to speak, to say" (see diction). Related: Interdicted; interdicting.
interdiction (n.) Look up interdiction at
mid-15c., enterdiccioun, from Latin interdictionem (nominative interdictio) "prohibition, interdiction," noun of action from past participle stem of interdicere (see interdict).
interdisciplinary (adj.) Look up interdisciplinary at
1937, from inter- + disciplinary.
interest (n.) Look up interest at
mid-15c., "legal claim or right; concern; benefit, advantage;" earlier interesse (late 14c.), from Anglo-French interesse "what one has a legal concern in," from Medieval Latin interesse "compensation for loss," noun use of Latin interresse "to concern, make a difference, be of importance," literally "to be between," from inter- "between" (see inter-) + esse "to be" (see essence).

Compare German Interesse, from the same Medieval Latin source. Form in English influenced 15c. by French interest "damage," from Latin interest "it is of importance, it makes a difference," third person singular present of interresse. Financial sense of "money paid for the use of money lent" (1520s) earlier was distinguished from usury (illegal under Church law) by being in reference to "compensation due from a defaulting debtor." Meaning "curiosity" is first attested 1771. Interest group is attested from 1907; interest rate by 1868.
interest (v.) Look up interest at
"to cause to be interested," c. 1600, earlier interesse (1560s), from the noun (see interest (n.)). Perhaps also from or influenced by interess'd, past participle of interesse.
interested (adj.) Look up interested at
"motivated by self-interest," 1705; "having an interest or stake (in something);" from past participle of interest (v.).
interesting (adj.) Look up interesting at
1711, "that concerns, important," from interest (v.). Meaning "so as to excite interest" is from 1768. Related: Interestingly. Euphemistic phrase interesting condition, etc., "pregnant" is from 1748.
interface Look up interface at
1882 (n.), 1967 (v.), from inter- + face. Related: Interfaced; interfacing.
interfaith (adj.) Look up interfaith at
1921, from inter- + faith.
interfere (v.) Look up interfere at
mid-15c., "to strike against," from Middle French enterferer "to strike each other," from entre- "between" (see entre-) + ferir "to strike," from Latin ferire "to knock, strike," related to Latin forare "to bore, pierce" (see bore (v.), and compare punch (v.), which has both the senses "to hit" and "to make a hole in"). Figurative sense of "to meddle with, oppose unrightfully" is from 1630s. Related: Interfered; interfering.