Sardonic comes from the Greek word sardonios, which is said to have originally referred to a plant that grew on the island of Sardinia and caused involuntary spasms of the face, similar to a grimace. In English, it has been used since the 17th century to describe speech or behavior that is mocking or cynical in nature. Sardonic humor is often used to comment on social or political issues, and is sometimes considered a form of satire. Today, sardonic is a commonly used word in English, and is often associated with a dark or biting sense of humor.