Meaning

• Something nasty.

  "Processed foods are full of aspartame and other nasties."

• (preceded by "the") Sexual intercourse.

• A video nasty.

Meaning

• Dirty, filthy.

• Contemptible, unpleasant (of a person).

• Objectionable, unpleasant (of a thing); repellent, offensive.

• Indecent or offensive; obscene, lewd.

• Spiteful, unkind.

• Awkward, difficult to navigate; dangerous.

• Grave or dangerous (of an accident, illness etc.).

• Formidable, terrific; wicked.