informer, n. 1. informant, appriser, notifier. See - informant.
2. tattletale, whistle blower, Inf. snitch, Inf. snitcher, All SI. fink, rat, ratfink, peacher, stool pigeon, stoolie, canary, nightingale, squealer, weasel.
3. spy, agent, secret agent, undercover agent, double agent, counterspy.
infraction, n. breach, violation, break, trespass, overstep; transgression, contravention, malfeasance, misfeasance; misdemeanor, wrongdoing, offense, law-breaking; infringement, intrusion, encroachment, invasion, poaching, Archaic, extravagation.
infrangible, adj. 1. unbreakable, indestructible, shatterproof, chip-proof, bulletproof, unshatterable; indivisible, undividable, indiscerptible, inseparable, impartible; insoluble, indissoluble, indissolvable, infusible; solid, dense, compact, tight, close, cohesive, thick.
2. inviolable, inalienable, inviolate; sacrosanct, sacred, holy, hallowed.
infrequency, n. 1. rarity, rareness, seldomness, unwontedness, infrequence; uncommonness, unusualness, exceptionality; irregularity, intermittence, occasionalness, occasionality, sporadicity.
2. fewness, scarcity, scarceness, scantness, scantiness, meagerness, sparseness.
infrequent, adj. 1. rare, seldom, seldom met, seldom seen, unfrequent, uncustomary; uncommon, unusual, exceptional, unwonted.
2. irregular, occasional, casual, incidental, every now and then, every now and again; sporadic, inconstant, intermittent.
3. few, scarce, spare, scant, sparse, meager; not many, few and far between, hardly any, not plentiful.
infringe, v. 1. break, disobey, violate, infract, breach; flout, fly in the face of, disregard, take no notice of; transgress, overstep, contravene.
2. encroach, move in on, impinge, squat; trespass, poach, invade, intrude, break into, broach, step over the line, trample on.
infringement, n. 1. disobedience, noncompliance, violation, infraction, breach, outrage, transgression, contravention, evasion, lawlessness.
2. encroachment, intrusion, inroad, incursion, infiltration, trespass, ingress, invasion; dispossession, seizure, usurpation, assumption, imposition; irruption, raid, foray, sally, sortie, drive.
infuriate, v. 1. enrage, madden, make [s.o.'s] blood boil, Inf. make [s.o.] see red; incense, anger, raise [s.o.'s] ire or hackles, get [s.o.'s] back up, Inf. get [s.o.'s] Irish or dander up, Inf. burn up, SI. tee off, SI. tick off; provoke, arouse, rouse, inflame, enflame, agitate, fire up, work up, stir up; vex, pique, irritate, annoy, irk, peeve, nettle, chafe, Chiefly U.S. rile, Inf. aggravate, Inf. miff, Inf. give [s.o.] a pain, Inf. get under [s.o.'s] skin, Inf. get in [s.o.'s] hair, SI. bug; exasperate, ruffle, roil, put out, get, SI. get [s.o's] goat, SI. freak [s.o.] out.
2. embitter, exacerbate, gall, rankle, envenom; affront, insult, offend, sting to the quick.
infuriated, adj. furious, enraged, raging, Rare, infuriate, fuming, very angry, horn-mad; wrathful, wroth, irate, ireful, incensed, in high dudgeon; inflamed, flaming, flaring, flared up, heated, red-hot, white-hot, hot under the collar; distraught, overwrought, Inf. in a dither, Inf. in a tizzy; indignant, up in arms, riled; worked up, agitated, stirred up; passionate, impassioned, impassionate, overexcited; upset, feverish, hysterical, not rational; violent, fierce, savage, unrestrained, uncontrollable; ranting, raving, Scot. redwood, storming, foaming at the mouth, rab