lament vs kvetch

lament and kvetch both are nouns.

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

As verbs, kvetch is a hypernym of lament; that is, kvetch is a word with a broader meaning than lament:

Other hypernyms of lament include complain, kick, plain, quetch, sound off.

lament (noun)	kvetch (noun)
a mournful poem; a lament for the dead	(Yiddish) a nagging complaint
a song or hymn of mourning composed or performed as a memorial to a dead person	(Yiddish) a constant complainer
a cry of sorrow and grief

lament (verb)	kvetch (verb)
regret strongly	express complaints, discontent, displeasure, or unhappiness
express grief verbally