gag vs belly laugh

gag and belly laugh both are nouns.

Word	Noun	Adjective	Verb	Adverb
gag	Yes	No	Yes	No
belly laugh	Yes	No	No	No

As nouns, belly laugh is a hyponym of gag; that is, belly laugh is a word with a more specific, narrower meaning than gag:

gag (noun)	belly laugh (noun)
restraint put into a person's mouth to prevent speaking or shouting	a joke that seems extremely funny
a humorous anecdote or remark intended to provoke laughter	a burst of deep loud hearty laughter

gag (verb)	belly laugh (verb)
struggle for breath; have insufficient oxygen intake
make an unsuccessful effort to vomit; strain to vomit
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