infertility, n. unfruitfulness, infecundity, aridness, unproductiveness, fallowness, fruitlessness; impotence, barrenness, sterility, effeteness, unprolificness. infest, v. overrun, take over, spread like wildfire, run through, overspread, pervade, permeate, penetrate, infiltrate; swarm, crawl, creep, throng; beset, plague, torment, drive crazy, discommode, incommode, discomfort, inconvenience; bother, annoy, pester, trouble, haunt. infidel, n. unbeliever, disbeliever, heathen, heretic, irreligionist; Turkish, giaour, pagan, alien, gentile; doubter, skeptic, nullifidian, scoffer, agnostic, freethinker. infidelity, n. 1. breach of trust, faithlessness, bad faith, treachery, perfidy, perfidiousness; disloyalty, unfaithfulness, falseness, falseheartedness; apostasy, traitorousness, Iscariotism, treason, recreancy; deceit, double-dealing, duplicity; disaffection, breach, estrangement.
2. adultery, cuckoldry, Law. criminal conversation, SI. fooling or playing around, SI. skipping or stepping out, SI. swinging, SI. running around, SI. getting some on the side, SI. cheating; intrigue, liaison, affair, amour, SI. hanky-panky; libertinism, licentiousness, unchastity, playing fast and loose. infiltrate, v. 1. pervade, permeate, interpenetrate, soak into, saturate, imbue, imbrue; percolate, filter through, seep, moisten, dampen.
2. intrude, slip or sneak in, creep into, invade, get behind the lines, get into the enemy camp, insinuate, penetrate. infinite, adj. 1. unlimited, limitless, without limit, illimitable, unbounded, boundless; inexhaustible, endless, unending, interminable, no end of, without end, bottomless; multitudinous, very great, enormous, prodigious, immense, vast, astronomical.
2. innumerable, innumerous, countless, untold, uncounted, numberless, myriad, without number, sum-less; unmeasured, indeterminate, undetermined, indefinite; undeterminable, indeterminable, incalculable, inestimable, uncountable, measureless, immeasurable, unmeasurable, fathomless, unfathomable.
3. perfect, whole, complete, total; omnipotent, allpowerful, all-encompassing, all-embracing.
4. eternal, everlasting, enduring, perpetual, undying, immortal, deathless; permanent, perdurable, unfading, imperishable, amaranthine, perennial; constant, unceasing, ceaseless, nonstop, unremitting, continuous, continual, ongoing, unbroken, uninterrupted, incessant, never-ending. infinitesimal, adj. 1. minute, tiny, very small, minuscule, microscopic, atomic, imperceptible; wee, little, diminutive, miniature; mini, midget, Lilliputian, pygmyish, dwarfish.
2. inappreciable, insignificant, inconsiderable, negligible; slight, puny, paltry, mere, meager, scanty, exigu ous; piddling, petty, trifling, Inf. picayune. infinity, n. 1. infinitude, infiniteness, unlimitedness, limitlessness, illimitability, illimitableness; unboundedness, boundlessness, bottomlessness, inexhaustibility, inexhaustibleness; enormousness, greatness, hugeness, prodigiousness, immensity, immenseness, vastness.
2. innumerableness, innumerability, unmeasuredness, indeterminateness, indefiniteness; undeterminableness, indeterminableness, incalculability, incalculableness, inestimability, inestimableness; measurelessness, unmeasurableness, fathomlessness.
3. perfection, perfectness, wholeness, completeness, totality, omnipotence.