adj. 1 offensive, loathsome, disgusting, obnoxious, revolting, repulsive, repellent, repugnant, sickening, nauseous, nauseating, nasty, beastly, Archaic fulsome The bartender makes a foul concoction he swears will cure a hangover 2 filthy, unclean, nasty, polluted, putrid, putrescent, putrefactive or putrefacient, defiled, soiled, spoiled, rotten, decayed, decomposed, rancid, soured, turned, tainted, mouldy, impure, adulterated, contaminated, stale, bad, Brit off The hamburger place was closed when public health inspectors found foul food in the freezer 3 smelly, stinking, noisome, fetid or foetid, rank, evil-smelling, foul-smelling, malodorous, musty, mephitic, graveolent A foul odour emanated from the cabinet 4 wicked, vile, bad, base, abominable, low, sordid, iniquitous, evil, flagitious, atrocious, monstrous, nefarious, sinful, immoral, amoral, vicious, villainous, scandalous, infamous, dishonourable, shameful, disgraceful, ignominious; detestable They were finally brought to justice for their foul deeds 5 dirty, obscene, filthy, profane, scatological, gross, smutty, foul-mouthed, blue, licentious, salacious, lewd, indecent, improper, coarse, uncouth, vulgar, rude, scurrilous, rough, indelicate, immodest, risqué, off colour, suggestive, bawdy, ribald, Rabelaisian, Fescennine, US raw, Slang raunchy My mother forbids my reading books containing foul language 6 abusive, offensive, affronting, insulting, disparaging, maligning, thersitical, calumnious or calumniatory, aspersive, slanderous, defamatory, libellous, denigrating, derogatory, deprecatory or deprecative, depreciatory or depreciative, denunciatory or denunciative, derisory, derisive, scornful, belittling, fulminous, objurgatory or objurgative, vituperative, invective Keep your foul tongue to yourself 7 dishonest, unfair, unjust, unsportsmanlike, dishonourable, fraudulent, underhand(ed), double-dealing, two-faced, corrupt, venal, dirty, treacherous, perfidious, traitorous, unscrupulous, Colloq crooked, shady, Slang chiefly Brit bent Thrupp will get his way by fair means or foul 8 nasty, dangerous, rough, disagreeable, unfavourable, sloppy, stormy, adverse; windy, blustery; snowy, sleety, wet, rainy We ran into a spot of foul weather at Dover 9 obstructed, blocked, choked, stopped (up), plugged (up), clogged (up) The drain is foul with all that rubbish 10 tangled, entangled, caught, ensnared, enmeshed, snarled A foul anchor is a common nautical symbol 11 illegal, prohibited, forbidden, interdicted, not fair; dirty In boxing a hit below the belt is a foul blow
v. 12 dirty, pollute, sully, befoul, defile, soil, contaminate, adulterate, taint Effluent from the factory was fouling the river 13 tangle, entangle, catch, snare, ensnare, enmesh, snag, snarl, jam, twist We can't hoist the mainsail because the halyard is fouled 14 disgrace, dishonour, sully, taint, besmirch, defile, soil, stain, smear, tarnish, blacken, denigrate, debase, degrade, abase, demean, disparage, defame, derogate, asperse, devaluate, depreciate, vitiate, belittle, discredit, bring or call into disrepute That act of treachery will foul the family name for generations 15 obstruct, block, choke, stop or plug or clog (up) Dead leaves fouled the downpipe 16 foul up. a See def. 13. b mismanage, mishandle, botch, bungle, make a mess (of), mess up, spoil, ruin, Colloq muff, Brit throw a spanner in(to) (the works), US throw a monkey wrench into (the machinery); Slang muck up, goof (up), blow, screw up, louse up, Chiefly Brit bugger (up), US and Canadian snafu Give him a chance and he's sure to foul up She fouled up my hi-fi.
n. 17 violation, infringement, infraction, illegality The Rangers' forward has already been charged with two fouls
adv. 18 afoul, in conflict, in trouble, in violation Curshaw has fallen foul of the law again