Definition of foul :
1. An entanglement; a collision, as in a boat race.
2. Covered with, or containing, extraneous matter which is injurious, noxious, offensive, or obstructive; filthy; dirty; not clean; polluted; nasty; defiled; as, a foul cloth; foul hands; a foul chimney; foul air; a ship's bottom is foul when overgrown with barnacles; a gun becomes foul from repeated firing; a well is foul with polluted water.
3. Hateful; detestable; shameful; odious; wretched.
4. Having freedom of motion interfered with by collision or entanglement; entangled; - opposed to clear; as, a rope or cable may get foul while paying it out.
5. In various games or sports, an act done contrary to the rules; a foul stroke, hit, play, or the like.
6. Loathsome; disgusting; as, a foul disease.
7. Not conformed to the established rules and customs of a game, conflict, test, etc.; unfair; dishonest; dishonorable; cheating; as, foul play.
8. Not favorable; unpropitious; not fair or advantageous; as, a foul wind; a foul road; cloudy or rainy; stormy; not fair; - said of the weather, sky, etc.
9. Scurrilous; obscene or profane; abusive; as, foul words; foul language.
10. See ball, under Foul, a.
11. To become clogged with burnt powder in the process of firing, as a gun.
12. To become entagled, as ropes; to come into collision with something; as, the two boats fouled.
13. To cover ( a ship's bottom) with anything that impered its sailing; as, a bottom fouled with barnacles.
14. To entangle, so as to impede motion; as, to foul a rope or cable in paying it out; to come into collision with; as, one boat fouled the other in a race.
15. To incrust ( the bore of a gun) with burnt powder in the process of firing.
16. To make filthy; to defile; to daub; to dirty; to soil; as, to foul the face or hands with mire.
17. Ugly; homely; poor.
mischievous, clean, maculate, ballpark, crude, vulgar, tempestuous, stenchy, uncleanly, appalling, stifle, muddied, noxious, bobble, flooded, defensive, decent, throttle, loathly, fouled, repellant, pernicious, bedraggled, good, besmirched, bawdy, gross, rebarbative, base, low-down, ill-scented, clot, short-tempered, blow, ground out, afoul, dreadful, cover, back up, muck up, choke off, come on, stained, musty, porny, severe, rich, queasy, muggy, tight, snuff it, scandalous, botch, sullied, lascivious, asphyxiate, ball boy, infamous, sickening, lewd, stormy, scurrilous, pixilated, shocking, bat, implike, boggle, horsepower, horrible, illegal, despicable, contemptible, draggled, choke down, cheating, ripe, profane, lousy, unprintable, tangled, malodorous, call, chip, yucky, skanky, offside, encounter, stinking, baulk, strong, corner, distasteful, drop dead, back, X-rated, conk, scatologic, trashy, impish, blue, ribald, awful, back off, befouled, bunt, pornographic, clog up, bungle, fight, cloud, despisable, Fescennine, broad, nauseating, unsavoury, decease, unethical, unholy, perish, engine, poisonous, dive, fierce, fusty, arch, sultry, gag, double, make a muck of, soiled, hit, muddle, bleak, ball girl, raw, buy the farm, wanton, die, temperamental, mess up, rotten, black, ball, mishandle, come into conflict with, gutter, cruddy, irritable, immoral, resistant, batboy, kick the bucket, pestilential, backhanded, bemired, pop off, pass away, fractious, back down, prankish, support, low, locker-room, deadly, humid, at bat, abhorrent, come off, reeky, fulsome, opprobrious, indecent, deleterious, corrupt, dishonest, inclement, grotty, exit, nauseous, bad-tempered, blast, illegible, freestyle, smelly, raunchy, smudged, rank, turbine, help, blank, drive, disgustful, harmful, unseasonable, puckish, rough, gum up, balk, stinky, baseline, antipathetic, unsavory, contaminating, begrimed, stag, touchy, strangle, detestable, ruinous, meet, barnyard, cross, go, coarse, mephitic, repelling, threatening, out-of-bounds, baseball, front, sensitive, goof up, correct, moody, suffocate, croak, frowsty, fumble, snafu, expire, foul-smelling, harsh, pain, rancid, horrendous, amoral, muff, ugly, screw up, deviant, hot-tempered, delivery, perverted, fret, crappy, two-cycle, unwholesome, scrag, backhand, dribble, ill-gotten, deny, chop down, noisome, vile, shitty, marked-up, foetid, perverting, ball up, frowsy, mismanage, louse up, dishonorable, unhealthful, like, blunder, bollix up, obnoxious, cash in one's chips, study at dirty, liter, overload, pass, reeking, injurious, turbulent, give-up the ghost, wretched, onside, pestiferous, fly, horrid, choke back, spoil, blackened, squally, unsporting, irascible, funky
evil (part of speech: adjective)
disgraceful, offensive, sinful, repugnant, terrible, detrimental, calamitous, monstrous, revolting, abominable, sinister, heinous, nefarious, evil, bad, repellent, damnable, repulsive, loathsome, destructive, hideous, wicked, baneful, atrocious, reprehensible
hinder (part of speech: verb)
cripple, block, thwart, burden, counter, congest, delay, oppose, baffle, inhibit, curb, snarl, obstruct, hamper, crimp, entrap, dam, fetter, constipate, mire, hamstring, constrain, complicate, deter, entangle, tangle, clog, snag, paralyze, stop, brake, handicap, detain, resist, restrain, hinder, stay, bung, frustrate, bar, impede, bottleneck, choke, jam, plug, drag, check, impair, cramp, restrict, encumber, catch, interrupt
dirty (part of speech: verb)
malevolent (part of speech: adjective)
hostile, nasty, venomous, spiteful, vindictive, hateful, catty, malignant, treacherous, antagonistic, vicious, ill-natured, mean, hurtful, bitter, perfidious, churlish, sullen, malicious, corrosive, malevolent, virulent, black-hearted, baleful, rancorous
unjust (part of speech: adjective)
unclean (part of speech: adjective)
scatological, shabby, crummy, sloppy, odious, unhygenic, impure, grungy, disgusting, insalubrious, scruffy, infectious, murky, obscene, toxic, sordid, mucky, filthy, untidy, unsanitary, icky, defiled, unclean, dingy, festering, dusty, squalid, putrid, smutty, grubby, grimy, septic, fetid, slovenly
- He would not be able to resume his journey and proceed to Denver for some time to come, but had laughed at the idea of any foul play. - "The House by the Lock", C. N. Williamson.
- He has no hope to get possession of her by fair means; foul are alone in his thoughts. - "The Lone Ranche", Captain Mayne Reid.
- You thought to play him a foul trick. - "The Hollow of Her Hand", George Barr McCutcheon.