sardonic (sahr-DON-ik) adjective
Marked by scorn, mockery, and cynicism.
"In no time the plot becomes less and less tangible as Merde Happens evolves into one long, sardonic diatribe by a Brit about the (exaggerated) strangeness of America -- when his French girlfriend isn't snarking about it." -Alan Wong; Sardonic Mirth; The Star, Kuala Lumpur, 5/9/08.
[After Sardinia, a large island in the Mediterranean. Eating a Sardinian plant was believed to produce facial convulsions as if in a maniacal laughter.]