Unpleasant or offensive in nature. The room had a nasty smell that made everyone feel uncomfortable.
Behaving in a spiteful or malicious way. She made a nasty comment about his appearance.
Dangerous or serious in nature. He suffered a nasty fall while hiking.
Difficult or unpleasant to deal with. The weather turned nasty, with heavy rain and strong winds.
Impressively good or skillful; formidable (slang). She delivered a nasty serve that her opponent couldn't return.
Sexually explicit or obscene in a way considered unpleasant or offensive. The comedian's routine was filled with nasty jokes that made some audience members uncomfortable.
Feeling or causing slight sickness or nausea. He felt nasty after eating only junk food all day.