Webster's Revised Unabridged Dictionary · 1913

Sardonic

Sardonic , adjective

[French sardonique, Latin sardonius, Greek {not transcribed}, {not transcribed}, perhaps from {not transcribed} to grin like a dog, or from a certain plant of Sardinia, Greek {not transcribed}, which was said to screw up the face of the eater.]

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. — Sir H. Wotton
The scornful, ferocious, sardonic grin of a bloody ruffian. — Burke
Collocations (1)
Sardonic grin or Sardonic laugh , an old medical term for a spasmodic affection of the muscles of the face, giving it an appearance of laughter.

Sardonic , adjective

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