sardonic

Scornfully or cynically mocking.

Given to making sardonic remarks.

Apparently but not really proceeding from gaiety; forced: said of a laugh or smile.

Bitterly ironical; sarcastic; derisive and malignant; sneering: now the usual meaning.

Of, pertaining to, or resembling, a kind of linen made at Colchis.

Forced; unnatural; insincere; hence, derisive, mocking, malignant, or bitterly sarcastic; — applied only to a laugh, smile, or some facial semblance of gayety.

an old medical term for a spasmodic affection of the muscles of the face, giving it an appearance of laughter.

Scornfully mocking or cynical.

Disdainfully or ironically humorous.