bemoan vs lament

bemoan is not a noun while lament is a noun.

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

As verbs, bemoan and lament are synonyms defined as:

Other synonyms of bemoan include bewail, deplore.

bemoan (noun)	lament (noun)
	a mournful poem; a lament for the dead
	a song or hymn of mourning composed or performed as a memorial to a dead person
	a cry of sorrow and grief

bemoan (verb)	lament (verb)
regret strongly	regret strongly
	express grief verbally