gag

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Something forced into or put over the mouth to prevent speaking or crying out.
2. n. An obstacle to or a censoring of free speech.
3. n. A device placed in the mouth to keep it open, as in dentistry.
4. n. A practical joke.
5. n. A comic effect or remark. See Synonyms at joke.
6. n. The act or an instance of gagging or choking.
7. v. To prevent from speaking or crying out by using a gag.
8. v. To stop or restrain from exercising free speech: censorship laws aimed at gagging the press.
9. v. To cause to choke, retch, or undergo a regurgitative spasm.
10. v. To keep (the mouth) open by using a gag.
11. v. To block off or obstruct (a pipe or valve, for example).
12. v. To experience a regurgitative spasm in the throat, as from revulsion to a food or smell or in reflexive response to an introduced object.
13. v. To retch or choke.
14. v. To make jokes or quips.

Century Dictionary and Cyclopedia

1. To stop up the mouth or throat of (a person) with some solid body, so as to prevent him from speaking; hence, to silence by authority or by violence; restrain from freedom of speech.
2. To pry or keep open by means of a gag.
3. To cause to heave with nausea.
4. To stop or choke up, as a valve or passage.
5. To introduce interpolations into: as, to gag a part.
6. To play jokes upon; joke; guy.
7. Synonyms Gag, Muzzle, Muffle; stifle. To gag is to silence by thrusting something into the mouth and securing it in place. To muzzle a dog, or other creature having a projecting mouth, is to incase the mouth and nose (muzzle) in a framework called a muzzle, in order to prevent him from biting or eating. Both gag and muzzle are sometimes used figuratively for the act of silencing effectively by moral compulsion, gag implying also roughness or severity in the performance: as, a muzzled press; to gag a public speaker by threats of violence. To muffle is primarily to conceal by wrapping up, but the word has a secondary use to express the deadening of sound, by wrapping (as an oar) or otherwise (as a drum).
8. To retch; heave with nausea.
9. To interpolate words of one's own into one's part: said of an actor.
10. n. Something thrust into the mouth or throat to prevent speech or outcry; hence, any violent or authoritative suppression of freedom of speech.
11. n. A mouthful which produces nausea and retching, or threatens with choking.
12. n. An apparatus or device for distending the jaws, such as is used in various surgical operations; hence, anything used to pry or keep open the jaws.
13. n. In coal-mining, a chip of wood in a sinking pit-bottom or sump.
14. n. An interpolation introduced by an actor into his part, whether in accordance with custom or with his own fancy.
15. n. A joke, especially a practical joke; a farce; a hoax.
16. n. A common name of Mycteroperca microlepis, a large serranoid fish, attaining a length of two or three feet: found on the southern Atlantic and Gulf coasts of the United States.

Wiktionary

1. abbr. group specific antigens
2. n. A device to restrain speech, such as a rag in the mouth secured with tape or a rubber ball threaded onto a cord or strap.
3. n. law An order or rule forbidding discussion of a case or subject.
4. n. A joke or other mischievous prank.
5. n. A convulsion of the upper digestive tract.
6. v. intransitive To experience the vomiting reflex.
7. v. this sense?) (U.S. Army, slang) To smoke: to order a recruit to exercise until he "gags" (usually spoken in exaggeration).
8. v. transitive To restrain someone's speech by blocking his or her mouth.
9. v. transitive, figuratively To restrain someone's speech without using physical means.

GNU Webster's 1913

1. v. To stop the mouth of, by thrusting sometimes in, so as to hinder speaking; hence, to silence by authority or by violence; not to allow freedom of speech to.
2. v. To pry or hold open by means of a gag.
3. v. To cause to heave with nausea.
4. v. To heave with nausea; to retch.
5. v. Slang To introduce gags or interpolations. See Gag, n., 3.
6. n. Something thrust into the mouth or throat to hinder speaking.
7. n. A mouthful that makes one retch; a choking bit.
8. n. Slang A speech or phrase interpolated offhand by an actor on the stage in his part as written, usually consisting of some seasonable or local allusion.

WordNet 3.0

1. n. a humorous anecdote or remark intended to provoke laughter
2. v. tie a gag around someone's mouth in order to silence them
3. v. prevent from speaking out
4. n. restraint put into a person's mouth to prevent speaking or shouting
5. v. struggle for breath; have insufficient oxygen intake
6. v. be too tight; rub or press
7. v. make jokes or quips
8. v. make an unsuccessful effort to vomit; strain to vomit
9. v. cause to retch or choke