A piece of cloth or other material used to cover someone's mouth to prevent them from speaking or making noise. The kidnappers used a gag to silence their captive.
A joke or a humorous story, especially one told by a comedian. The comedian's gag about the airline food had the audience in stitches.
A restriction or censorship imposed on free speech or expression. The new law was criticized as a gag on the press.
A reflex contraction of the muscles of the throat that prevents choking; the retch reflex. The dentist's mirror brought on a sudden gag.