What is the meaning of gag?

noun

• A humorous anecdote or remark intended to provoke laughter.
  • usage: "he told a very funny joke"; "he knows a million gags"; "thanks for the laugh"; "he laughed unpleasantly at his own jest"; "even a schoolboy's jape is supposed to have some ascertainable point"
  • synonyms: joke, laugh, jest, jape
• Restraint put into a person's mouth to prevent speaking or shouting.
  • synonyms: muzzle

verb

• Prevent from speaking out.
  • usage: "The press was gagged"
  • synonyms: muzzle
• Be too tight; rub or press.
  • usage: "This neckband is choking the cat"
  • synonyms: choke, fret
• Tie a gag around someone's mouth in order to silence them.
  • usage: "The burglars gagged the home owner and tied him to a chair"
  • synonyms: muzzle
• Make jokes or quips.
  • usage: "The students were gagging during dinner"
  • synonyms: quip
• Struggle for breath; have insufficient oxygen intake.
  • usage: "he swallowed a fishbone and gagged"
  • synonyms: choke, strangle, suffocate
• Cause to retch or choke.
  • synonyms: choke
• Make an unsuccessful effort to vomit; strain to vomit.
  • synonyms: heave, retch