Meaning of “gag” - Learner’s Dictionary

gag

verb uk us /ɡæɡ/ (present participle gagging, past tense and past participle gagged)
COVER MOUTH [ T ]

to fasten something over someone's mouth so that they cannot speak:

The owners of the house were found bound and gagged in the cellar.
STOP INFORMATION [ T ]

to prevent someone from giving their opinion or giving information about something:

The government is trying to gag the press over the issue.
ALMOST VOMIT [ I ]

to feel that you are going to vomit:

The sight of the body made him gag.

(Definition of “gag verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)