GAG

noun

1. 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.
2. An order or rule forbidding discussion of a case or subject.
3. A joke or other mischievous prank.

verb

1. To experience the vomiting reflex.
2. To cause to heave with nausea.
3. To restrain someone's speech by blocking his or her mouth.