Sardonic /(?)/

Sar·don·ic

Sardonic

a.
  1. Forced; unnatural; insincere; hence, derisive, mocking, malignant, or bitterly sarcastic; -- applied only to a laugh, smile, or some facial semblance of gayety.
    Where strained, sardonic smiles are glozing still, And grief is forced to laugh against her will.
    The scornful, ferocious, sardonic grin of a bloody ruffian.

Phrases & Compounds
Sardonic grin
an old medical term for a spasmodic affection of the muscles of the face, giving it an appearance of laughter.

Sardonic

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