sorrower vs wailer

sorrower and wailer both are nouns.

Word	Noun	Adjective	Verb	Adverb
sorrower	Yes	No	No	No
wailer	Yes	No	No	No

As nouns, wailer is a hyponym of sorrower; that is, wailer is a word with a more specific, narrower meaning than sorrower:

sorrower: a person who is feeling grief (as grieving over someone who has died)
wailer: a mourner who utters long loud high-pitched cries

Other hyponyms of sorrower include bearer, pallbearer, weeper.

sorrower (noun)	wailer (noun)
a person who is feeling grief (as grieving over someone who has died)	a mourner who utters long loud high-pitched cries