nasty

a. [ Compar. Nastier superl. Nastiest. ] [ For older nasky; cf. dial. Sw. naskug, nasket. ] 1. Offensively filthy; very dirty, foul, or defiled; disgusting; nauseous. [ 1913 Webster ]

2. Hence, loosely: Offensive; disagreeable; unpropitious; wet; drizzling; as, a nasty rain, day, sky. [ 1913 Webster ]

3. Characterized by obscenity; indecent; indelicate; gross; filthy. [ 1913 Webster ]

4. Vicious; offensively ill-tempered; insultingly mean; spiteful; as, a nasty disposition. [ PJC ]

5. Difficult to deal with; troublesome; as, he fell of his bike and got a nasty bruise on his knee. [ slang ] [ PJC ]

Syn. -- Nasty, Filthy, Foul, Dirty. Anything nasty is usually wet or damp as well as filthy or dirty, and disgusts by its stickiness or odor; but filthy and foul imply that a thing is filled or covered with offensive matter, while dirty describes it as defiled or sullied with dirt of any kind; as, filthy clothing, foul vapors, etc. [ 1913 Webster ]