influence (n.) Look up influence at Dictionary.com
late 14c., an astrological term, "streaming ethereal power from the stars when in certain positions, acting upon character or destiny of men," from Old French influence "emanation from the stars that acts upon one's character and destiny" (13c.), also "a flow of water, a flowing in," from Medieval Latin influentia "a flowing in" (also used in the astrological sense), from Latin influentem (nominative influens), present participle of influere "to flow into, stream in, pour in," from in- "into, in, on, upon" (see in- (2)) + fluere "to flow" (see fluent).

The range of senses in Middle English were non-personal, in reference to any outflowing of energy that produces effect, of fluid or vaporous substance as well as immaterial or unobservable forces. Meaning "exertion of unseen influence by persons" is from 1580s (a sense already in Medieval Latin, for instance Aquinas); meaning "capacity for producing effects by insensible or invisible means" is from 1650s. Under the influence (of alcohol, etc.) "drunk" first attested 1866.
influent (adj.) Look up influent at Dictionary.com
mid-15c., "abundant, flowing in," in reference to occult power of the stars, etc., also of grace, from Latin influentem (nominative influens) "flowing in," present participle of influere "to flow in" (see influence (n.)). Also occasionally in the sense "influential" (1630s).
influential (adj.) Look up influential at Dictionary.com
"powerful, having influence," 1650s, from Medieval Latin influentialis, from influentia (see influence (n.)). Earlier in an astrological sense (1560s). Related: Influentially.
influenza (n.) Look up influenza at Dictionary.com
1743, borrowed (during an outbreak of the disease in Europe), from Italian influenza "influenza, epidemic," originally "visitation, influence (of the stars)," from Medieval Latin influentia in the astrological sense (see influence).
AN Article from Rome informs us that a Sort of Plague has broke out there, which destroys Abundance of their People, and they call it the Influenza. ["The Gentleman's Magazine," April 1743]
Used in Italian for diseases since at least 1504 (as in influenza di febbre scarlattina "scarlet fever") on notion of astral, occult, or atmospheric influence. The 1743 outbreak began in Italy. Often applied since mid-19c. to severe colds.
influx (n.) Look up influx at Dictionary.com
1620s, from French influx (16c.) or directly from Late Latin influxus "a flowing in," from past participle stem of Latin influere "to flow in" (see influence (n.)). Originally of rivers, air, light, spiritual light, etc.; used of people from 1650s.
info (n.) Look up info at Dictionary.com
1906, short for information.
info- Look up info- at Dictionary.com
word-forming element abstracted from information.
infold (n.) Look up infold at Dictionary.com
see enfold. Related: Infolded; infolding.
infomercial (n.) Look up infomercial at Dictionary.com
1983, from info- + commercial (n.). Before the televised infomercial was the newspaper advertorial (1961).
inform (v.) Look up inform at Dictionary.com
early 14c., "to train or instruct in some specific subject," from Old French informer, enformer "instruct, teach" (13c.) and directly from Latin informare "to shape, give form to, delineate," figuratively "train, instruct, educate," from in- "into" (see in- (2)) + formare "to form, shape," from forma "form" (see form (n.)). In early use also enform until c. 1600. Sense of "report facts or news, communicate information to" first recorded late 14c. Related: Informed; informing.
informal (adj.) Look up informal at Dictionary.com
mid-15c., "lacking form; not in accordance with the rules of formal logic," from in- (1) "not, opposite of" + formal (adj.). Meaning "irregular, unofficial, not according to rule or custom" is from c. 1600. Sense of "done without ceremony" is from 1828. Related: Informally.
informality (n.) Look up informality at Dictionary.com
1590s, from informal + -ity.
informant (n.) Look up informant at Dictionary.com
1690s, "someone who supplies information," from Latin informantem (nominative informans), present participle of informare "train, instruct, educate" (see inform). Occasionally as "one who gives information to the authorities, one who dishonorably betrays knowledge gained in confidence" (1783). Informer is older in both senses and more usual in the latter. As an adjective from 1890.
informatics (n.) Look up informatics at Dictionary.com
1967, translating Russian informatika (1966); see information + -ics.
information (n.) Look up information at Dictionary.com
late 14c., informacion, "act of informing, communication of news," from Old French informacion, enformacion "advice, instruction," from Latin informationem (nominative informatio) "outline, concept, idea," noun of action from past participle stem of informare "to train, instruct, educate; shape, give form to" (see inform). The restored Latin spelling is from 16c.

Meaning "knowledge communicated concerning a particular topic" is from mid-15c. The word was used in reference to television broadcast signals from 1937; to punch-card operating systems from 1944; to DNA from 1953. Information theory is from 1950; information technology is from 1958 (coined in "Harvard Business Review"); information revolution, to be brought about by advances in computing, is from 1966. Information overload is by 1967.
informational (adj.) Look up informational at Dictionary.com
1810, from information + -al (1).
informative (adj.) Look up informative at Dictionary.com
1650s, "instructive, didactic," from Medieval Latin informativus, from Latin informatus, past participle of informare "to train, instruct, educate" (see inform). In Middle English, the same word meant "formative, shaping, plastic, having power to form or animate" (late 14c.). Related: Informatively.
informed (adj.) Look up informed at Dictionary.com
1540s, "current in information," past-participle adjective from inform (v.). In 16c.-17c. it also could mean "unformed, formless," from in- (1) "not, opposite of," and was used in astronomy of stars that did not form part of the visual pattern of a constellation but were within it.
informer (n.) Look up informer at Dictionary.com
late 14c., enfourmer "instructor, one who teaches or gives advice," from inform (Middle English enfourmen) and also from Old French enformeor. Meaning "one who communicates information" is mid-15c.; sense of "one who gives information against another" (especially in reference to law-breaking) is c. 1500.
infortunate (adj.) Look up infortunate at Dictionary.com
"unlucky, luckless," late 14c., from Latin infortunatus, from in- "not, opposite of" (see in- (1)) + fortunatus "prospered, prosperous; lucky, happy" (see fortunate (adj.)). Also used in medieval astrology in reference to the supposed malevolent influence of certain positions or combinations of planets. The word lies beneath the "obsolete" headstone in OED. Related: infortune (n.); infortunacy.
infotainment (n.) Look up infotainment at Dictionary.com
1983, from info- + entertainment.
infra (adv.) Look up infra at Dictionary.com
"under, below, further on," from Latin infra "below, under, beneath" (see infra-). A Latin word sometimes encountered in footnotes.
infra dig. Look up infra dig. at Dictionary.com
"beneath one's dignity, unbecoming to one's position in society," 1824, colloquial abbreviation of Latin infra dignitatem "beneath the dignity of." See infra- + dignity.
infra- Look up infra- at Dictionary.com
word-forming element meaning "below, beneath," from Latin infra (adverb and preposition) "below, underneath, on the under side, beneath," also "later than; smaller than; inferior to," related to infernus "low, below," from PIE *ndher "under" (cognates: Sanskrit adnah "below," Old English under "under, among;" see under). Modern popular use of it dates from the 1920s, as an opposite to super-, often in science fiction. "This use of infra- is scarcely a Latin one" [OED].
infra-red (adj.) Look up infra-red at Dictionary.com
also infrared, 1873, "below the red" (in the spectrum), from infra- + red (adj.1). As a noun, also from 1873.
infraction (n.) Look up infraction at Dictionary.com
mid-15c., "the breaking of an agreement," from Old French infraction (13c.) and directly from Latin infractionem (nominative infractio) "a breaking, weakening," noun of action from past participle stem of infringere "to damage, break off, break, bruise," from in- "in" (see in- (2)) + frangere "to break" (see fraction). The verb infract (1560s) is archaic.
infralapsarian (adj.) Look up infralapsarian at Dictionary.com
1731, from infra- + Latin lapsus "a fall" (see lapse (n.)) + ending from unitarian, etc.
[In theology], the doctrine held by Augustinians and by many Calvinists, that God planned the creation, permitted the fall, elected a chosen number, planned their redemption, and suffered the remainder to be eternally punished. The Sublapsarians believe that God did not permit but foresaw the fall, while the Supralapsarians hold that God not only permitted but decreed it. [Century Dictionary]
infrasonic (adj.) Look up infrasonic at Dictionary.com
also infra-sonic, 1920, on the model of supersonic, etc., from infra- + sonic. Or perhaps modeled on French infra-sonore.
infrastructure (n.) Look up infrastructure at Dictionary.com
1887, from French infrastructure (1875); see infra- + structure (n.). The installations that form the basis for any operation or system. Originally in a military sense.
infrequency (n.) Look up infrequency at Dictionary.com
1670s, fact of being infrequent," from Latin infrequentia "a small number, thinness, scantiness," noun of quality from infrequentem (nominative infrequens) "occurring seldom, unusual; not crowded, absent," from in- "not" (see in- (1)) + frequens (see frequent). Older in this sense is infrequence (1640s). Earlier infrequency was used in a now-obsolete sense of "state of being unfrequented" (c. 1600).
infrequent (adj.) Look up infrequent at Dictionary.com
1530s, "little used" (now obsolete); 1610s, "not occurring often," from Latin infrequentem (nominative infrequens) "occurring seldom, unusual; not crowded, absent," from in- "not" (see in- (1)) + frequens "repeated, regular, constant, often" (see frequent). Related: Infrequently.
infrigidation (n.) Look up infrigidation at Dictionary.com
early 15c., in medicine, "a making cold, cooling; a state of coolness," from Late Latin infrigidationem (nominative infrigidatio) "a cooling," noun of action from past participle stem of infrigidare "to make cold," from in- "in, into" (see in- (2)) + frigidare, from frigidus "cold" (see frigid). A verb infrigidate is attested from 1540s.
infringe (v.) Look up infringe at Dictionary.com
mid-15c., enfrangen, "to violate," from Latin infringere "to damage, break off, break, bruise," from in- "in" (see in- (2)) + frangere "to break" (see fraction). Meaning "encroach" first recorded c. 1760. Related: Infringed; infringing.
infringement (n.) Look up infringement at Dictionary.com
"a break or breach" (of a contract, right, etc.), from infringe + -ment. Earlier in a now-obsolete sense of "contradiction" (1590s).
infundibulum (n.) Look up infundibulum at Dictionary.com
1799, "funnel-shaped organ or body part," from a Modern Latin use of Latin infundibulum "a funnel," from infundere "to pour into" (see infuse) + -bulum, suffix forming names of instruments. In some cases a loan-translation into Latin of Greek khoane "funnel." Related: Infundibular.
infuriate (v.) Look up infuriate at Dictionary.com
1660s, from Italian infuriato, from Medieval Latin infuriatus, past participle of infuriare "to madden, enrage," from Latin in furia "in a fury," from ablative of furia (see fury). Also from 1660s as an adjective in English, but this use is rare. Related: Infuriated; infuriating.
infuriating (adj.) Look up infuriating at Dictionary.com
1874, present participle adjective from infuriate (v.). Related: Infuriatingly.
infuriation (n.) Look up infuriation at Dictionary.com
1791, noun of action from infuriate (v.).
infuse (v.) Look up infuse at Dictionary.com
early 15c., "to pour in, introduce, soak (something in liquid)," from Latin infusus, past participle of infundere "to pour into, pour out; press in, crowd in; mix, mingle," from in- "in" (see in- (2)) + fundere "pour, spread" (see found (v.2)). Related: Infused; infusing; infusory; infusorial.
infusion (n.) Look up infusion at Dictionary.com
c. 1400, "a liquid extract (obtained by soaking in water);" early 15c., "a pouring in; that which is poured in," from Old French infusion "injection" (13c.) or directly from Latin infusionem (nominative infusio) "a pouring in, a watering," noun of action from past participle stem of infundere "to pour into" (see infuse).
Inga Look up Inga at Dictionary.com
fem. proper name, usually a shortening of Ingrid (q.v.).
ingenious (adj.) Look up ingenious at Dictionary.com
early 15c., "intellectual, talented," from Middle French ingénieux "clever, ingenious" (Old French engeignos), from Latin ingeniosus "of good natural capacity, full of intellect, clever, gifted with genius," from ingenium "innate qualities, ability; inborn character," literally "that which is inborn," from in- "in" (see in- (2)) + gignere, from PIE *gen(e)-yo-, suffixed form of root *gen- "to give birth, beget, produce" (see genus).

Sense of "skillful, crafty, clever at contrivance" first recorded 1540s; earlier in this sense was Middle English enginous (mid-14c.), from Old French engeignos. Middle English also had engineful "skillful (in war)" (c. 1300). By a direct path, Latin ingenium produced Middle English ingeny "intellectual capacity, cleverness" (early 15c.), but this is obsolete. Compare engine. Related: Ingeniously; ingeniousness.
ingenue (n.) Look up ingenue at Dictionary.com
"young woman who displays innocent candor or simplicity," 1848, from French ingénue "artless girl," especially as a character on the stage, noun use of fem. of ingénu "ingenuous, artless, simple" (13c.), from Latin ingenuus "frank, upright, candid," originally "free-born" (see ingenuous). Italicized in English into 20c.
ingenuity (n.) Look up ingenuity at Dictionary.com
1590s, "honor, nobility," from Middle French ingénuité "quality of freedom by birth" and directly from Latin ingenuitatem (nominative ingenuitas) "condition of a free-born man," figuratively "frankness, generosity, noble-mindedness," from ingenuus "frank, candid, noble" (see ingenuous).

Etymologically, this word belongs to ingenuous, but in 17c. ingenious "intellectual, talented" and ingenuous so often were confused (even by Shakespeare) that ingenuity in English has come to mean only "capacity for invention or construction." That sense of this word is first attested 1640s; the word for it in Middle English was ingeniosity (the native word is craftiness). French ingénuité has evolved through "natural and graceful freedom of manners" to "graceful simplicity" (compare ingenue); for the sense "ingeniousness," French uses ingénuosité.
ingenuous (adj.) Look up ingenuous at Dictionary.com
1590s, "noble in nature, high-minded; honorably straightforward," from Latin ingenuus "with the virtues of freeborn people, of noble character, frank, upright, candid," originally "native, freeborn," literally "born in (a place)," from in- "in" (see in- (2)) + PIE *gen(e)-wo-, suffixed form of root gene- "to give birth, beget, produce" (see genus). Sense of "artless, innocent" is 1670s, via evolution from "honorably open, straightforward," to "innocently frank." Related: Ingenuously; ingenuousness.
ingest (v.) Look up ingest at Dictionary.com
1610s, "to take in as food," from Latin ingestus, past participle of ingerere "to throw in, pour in, heap upon," from in- "into" (see in- (2)) + gerere "to carry" (see gest). Related: Ingested; ingesting.
ingestion (n.) Look up ingestion at Dictionary.com
"action of ingesting," 1610s, from Late Latin ingestionem (nominative ingestio) "a pouring in," noun of action from past participle stem of ingerere "pour in" (see ingest).
ingle (n.1) Look up ingle at Dictionary.com
"fireplace," c. 1500, from Scottish, usually said to be from Gaelic aingeal "fire, light" ("but there are difficulties" [OED]), a word of uncertain origin. The vogue for Scottish poetry in late 18c. introduced ingleside "fireside" (1747) and ingle-nook "corner by the fire" (1773) to literary English.
ingle (n.2) Look up ingle at Dictionary.com
"boy favorite, catamite," 1590s, of uncertain origin.
inglorious (adj.) Look up inglorious at Dictionary.com
"with bad fame, dishonorable," 1570s, from in- (1) "not, opposite of" + glorious. Latin ingloriosus meant "without fame, unhonored, inconspicuous, without trophies." The classical sense "without fame, obscure" is attested in the English word from 1590s but is marked "rare" in OED. Related: Ingloriously; ingloriousness.