adjective
(now chiefly US) Dirty, filthy.
Contemptible, unpleasant (of a person).
Objectionable, unpleasant (of a thing); repellent, offensive.
Indecent or offensive; obscene, lewd.
Spiteful, unkind.
(chiefly UK) Awkward, difficult to navigate; dangerous.
(chiefly UK) Grave or dangerous (of an accident, illness etc.).
(slang, chiefly US) Formidable, terrific; wicked.
noun
(informal) Something nasty.
(euphemistic, slang, preceded by "the") Sexual intercourse.
A video nasty.