kvetch vs bellyache

kvetch and bellyache both are nouns.

Word	Noun	Adjective	Verb	Adverb
kvetch	Yes	No	Yes	No
bellyache	Yes	No	Yes	No

As verbs, bellyache is a hyponym of kvetch; that is, bellyache is a word with a more specific, narrower meaning than kvetch:

kvetch (noun)	bellyache (noun)
(Yiddish) a nagging complaint	an ache localized in the stomach or abdominal region
(Yiddish) a constant complainer

kvetch (verb)	bellyache (verb)
express complaints, discontent, displeasure, or unhappiness	complain