The word "gag" is commonly used to describe a physical restraint imposed on someone's mouth to prevent them from speaking or screaming. Other synonyms for "gag" include muzzle, restraint, clamp, binding, and hush. However, "gag" can also be used in the context of humor to describe a joke or prank that is meant to elicit a strong, involuntary response of laughter. In this sense, synonyms for "gag" might include quip, practical joke, prank, or jape. Regardless of the context, the word "gag" carries with it a connotation of restraint or stifling, whether physical or psychological.