<p><strong>Adjective:</strong></p><ul><li>dirtier, dirtiest.</li><li>soiled with dirt; foul; unclean:<ul><li>"dirty laundry."</li></ul></li><li>Synonyms: unclean, grimy</li><li>spreading or imparting dirt; soiling:<ul><li>"dirty smoke."</li></ul></li><li>vile; mean; sordid; contemptible:<ul><li>"to play a dirty trick on someone."</li></ul></li><li>Synonyms: shabby, low, execrable, despicable, base</li><li>obscene; pornographic; indecent:<ul><li>"a dirty joke."</li></ul></li><li>Synonyms: vulgar, raunchy, lewd, nasty, lascivious</li><li>undesirable or unpleasant; thankless:<ul><li>"He left the dirty work for me."</li></ul></li><li>very unfortunate or regrettable:<ul><li>"That's a dirty shame!"</li></ul></li><li>not fair or sportsmanlike; unscrupulous:<ul><li>"a dirty fighter."</li></ul></li><li>hostile, insulting, contemptuous, or resentful:<ul><li>"She gave me a dirty look."</li><li>"He made a dirty crack about the cooking."</li></ul></li><li>(of a nuclear weapon) producing a relatively large amount of radioactive fallout.</li><li>(of the weather) stormy; squally:<ul><li>"It looks dirty to windward."</li></ul></li><li>Synonyms: nasty, inclement, foul, rainy</li><li>Informal: obtained through illegal or disreputable means:<ul><li>"dirty money."</li></ul></li><li>appearing as if soiled; dark-colored; dingy; drab.</li><li>Synonyms: dull</li></ul><p><strong>Verb (used with or without object):</strong></p><ul><li>dirtied, dirtying.</li><li>to make or become dirty.</li><li>Synonyms: sully, befoul, soil</li></ul><p><strong>Adverb:</strong></p><ul><li>Informal: in a mean, unscrupulous, or underhand way:<ul><li>"to play dirty."</li></ul></li><li>Informal: in a lewd manner:<ul><li>"to talk dirty."</li></ul></li></ul>