Sardonic grin is a facial expression that conveys mocking or sarcastic amusement. It can also signal disbelief or cynicism. Synonyms for sardonic grin include grimace, sneer, smirk, derisive smile, taunting smile, and twisted smile. These expressions all indicate a lack of sincerity and a mocking attitude. A grimace may be more associated with pain or discomfort, while a sneer may involve more contempt. A smirk is often used to show a sense of superiority, while a derisive smile may indicate ridicule. A taunting smile is often meant to provoke or annoy, while a twisted smile may suggest evil intentions.