Something nasty.
(preceded by "the") Sexual intercourse.
A video nasty.
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.