dirty

adj., adv., & v.
—adj. (dirtier, dirtiest)
1 soiled, unclean.
2 causing one to become dirty (a dirty job).
3 sordid, lewd; morally illicit or questionable (dirty joke).
4 unpleasant, nasty.
5 dishonest, dishonourable, unfair (dirty play).
6 (of weather) rough, squally.
7 (of a colour) not pure or clear, dingy.
8 colloq. (of a nuclear weapon) producing considerable radioactive fallout.
—adv. sl. (with adjectives expressing magnitude) very (a dirty great diamond).
—v.tr. & intr. (-ies, -ied) make or become dirty.
Phrases and idioms:
dirty dog colloq. a scoundrel; a despicable person. the dirty end of the stick colloq. the difficult or unpleasant part of an undertaking, situation, etc. dirty linen (or washing) colloq. intimate secrets, esp. of a scandalous nature. dirty look colloq. a look of disapproval, anger, or disgust. dirty money extra money paid to those who handle dirty materials. dirty trick
1 a dishonourable and deceitful act.
2 (in pl.) underhand political activity, esp. to discredit an opponent. dirty weekend colloq. a weekend spent clandestinely with a lover.
dirty word
1 an offensive or indecent word.
2 a word for something which is disapproved of (profit is a dirty word). dirty work dishonourable or illegal activity, esp. done clandestinely. do the dirty on colloq. play a mean trick on.
Derivatives:
dirtily adv. dirtiness n.