Merriam-Webster's Collegiate® Dictionary, 11th Edition
GAG
I. verb (gagged; gagging)
Etymology: Middle English gaggen to strangle, of imitative origin
Date: 1509
transitive verb
1. to restrict use of the mouth of by inserting a gag, to prevent from exercising freedom of speech or expression, to pry or hold open with a gag, to provide or write quips or pranks for , to choke or cause to retch, intransitive verb
1. choke , retch , to be unable to endure something ; balk , to make quips, gagger noun
II. noun
Date: 1530
something thrust into the mouth to keep it open or to prevent speech or outcry, an official check or restraint on debate or free speech , a laugh-provoking remark or act, prank , trick