Definition of "Gag" :
noun: restraint put into a person's mouth to prevent speaking or shouting
noun: a humorous anecdote or remark intended to provoke laughter
"He knows a million gags."
verb: make an unsuccessful effort to vomit; strain to vomit
verb: cause to retch or choke
verb: struggle for breath; have insufficient oxygen intake
"He swallowed a fishbone and gagged."
verb: make jokes or quips
"The students were gagging during dinner."
verb: tie a gag around someone's mouth in order to silence them
"The burglars gagged the home owner and tied him to a chair."
verb: be too tight; rub or press
verb: prevent from speaking out
"The press was gagged."