gag vs joke

gag and joke both are nouns.

Word	Noun	Adjective	Verb	Adverb
gag	Yes	No	Yes	No
joke	Yes	No	Yes	No

As nouns, gag and joke are synonyms defined as:

gag and joke: a humorous anecdote or remark intended to provoke laughter

Other synonyms of gag include jape, jest, laugh.

As verbs, joke is a hypernym of gag; that is, joke is a word with a broader meaning than gag:

Other hypernyms of gag include jest.

gag (noun)	joke (noun)
restraint put into a person's mouth to prevent speaking or shouting	a ludicrous or grotesque act done for fun and amusement
a humorous anecdote or remark intended to provoke laughter	activity characterized by good humor
	a triviality not to be taken seriously
	a humorous anecdote or remark intended to provoke laughter

gag (verb)	joke (verb)
struggle for breath; have insufficient oxygen intake	act in a funny or teasing way
make an unsuccessful effort to vomit; strain to vomit	tell a joke; speak humorously
cause to retch or choke
make jokes or quips
be too tight; rub or press
tie a gag around someone's mouth in order to silence them
prevent from speaking out