Sardonic
/sɑːrˈdɒnɪk/ adjective mediumMocking or scornful in a dry, biting way, often through sarcasm.
He gave a sardonic smile and said, 'Wonderful, another meeting that could have been an email.'
Memory Trick
Legend traces sardonic to a bitter Sardinian plant said to twist the face into a grim, mocking smile as it poisoned you -- a sardonic grin still looks like that same twisted smirk.