# adjective. - highly unpleasant, especially to the senses; physically nauseating. * plastic bags burn with a nasty, acrid smell - (of a person or animal) behaving in an unpleasant or spiteful way. * Harry was a nasty, foul-mouthed old devil - physically or mentally damaging or harmful. * a nasty, vicious-looking hatchet
# noun. - an unpleasant or harmful person or thing. * bacteria and other nasties