pallbearer vs lamenter

pallbearer and lamenter both are nouns.

Word	Noun	Adjective	Verb	Adverb
pallbearer	Yes	No	No	No
lamenter	Yes	No	No	No

As nouns, lamenter is a hypernym of pallbearer; that is, lamenter is a word with a broader meaning than pallbearer:

pallbearer: one of the mourners carrying the coffin at a funeral
lamenter: a person who is feeling grief (as grieving over someone who has died)

Other hypernyms of pallbearer include griever, mourner, sorrower.

pallbearer (noun)	lamenter (noun)
one of the mourners carrying the coffin at a funeral	a person who is feeling grief (as grieving over someone who has died)