adj. (nastier, nastiest) 1 a highly unpleasant (a nasty experience). b annoying; objectionable (the car has a nasty habit of breaking down). 2 difficult to negotiate; dangerous, serious (a nasty fence; a nasty question; a nasty illness). 3 (of a person or animal) ill-natured, ill-tempered, spiteful; violent, offensive (nasty to his mother; turns nasty when he's drunk). 4 (of the weather) foul, wet, stormy. 5 a disgustingly dirty, filthy. b unpalatable; disagreeable (nasty smell). c (of a wound) septic. 6 a obscene. b delighting in obscenity. a nasty bit (or piece) of work colloq. an unpleasant or contemptible person. a nasty one 1 a rebuff; a snub. 2 an awkward question. 3 a disabling blow etc. nastily adv. nastiness n.
[ ME: orig. unkn. ]