adj. 25B6; adjective
a dirty sweatshirt 007C; dirty water : SOILED, grimy, grubby, filthy, mucky, stained, unwashed, greasy, smeared, smeary, spotted, smudged, cloudy, muddy, dusty, sooty; unclean, sullied, impure, tarnished, polluted, contaminated, defiled, foul, unhygienic, insanitary, unsanitary; informal cruddy, yucky, icky; Brit. informal manky, gungy, grotty; poetic/literary befouled, besmirched, begrimed.
a dirty joke : INDECENT, obscene, rude, naughty, vulgar, smutty, coarse, crude, filthy, bawdy, suggestive, ribald, racy, salacious, risqué, offensive, off colour, lewd, pornographic, explicit, X-rated; informal blue; euphemistic adult.
dirty tricks : DISHONEST, deceitful, unscrupulous, dishonourable, unsporting, ungentlemanly, below the belt, unfair, unethical, unprincipled; crooked, double-dealing, underhand, sly, crafty, devious, sneaky; Brit. informal out of order, not cricket.
(informal) a dirty cheat : DESPICABLE, contemptible, hateful, vile, low, mean, unworthy, worthless, beyond contempt, sordid; informal rotten; archaic scurvy.
a dirty look : MALEVOLENT, resentful, hostile, black, dark; angry, cross, indignant, annoyed, disapproving; informal peeved.
dirty weather : UNPLEASANT, nasty, foul, inclement, bad; rough, stormy, squally, gusty, windy, blowy, rainy; murky, overcast, louring.
clean, innocent, honourable, pleasant.
25B6; verb the dog had dirtied her dress : SOIL, stain, muddy, blacken, mess up, mark, spatter, bespatter, smudge, smear, splatter; sully, pollute, foul, defile; poetic/literary befoul, besmirch, begrime.
clean.