sorrow vs keen

sorrow and keen both are nouns.

Word	Noun	Adjective	Verb	Adverb
sorrow	Yes	No	Yes	No
keen	Yes	Yes	Yes	No

sorrow (noun)	keen (noun)
something that causes great unhappiness	a funeral lament sung with loud wailing
an emotion of great sadness associated with loss or bereavement
sadness associated with some wrong done or some disappointment
the state of being sad

sorrow (adjective)	keen (adjective)
	excellent
	intense or sharp
	having or demonstrating ability to recognize or draw fine distinctions
	having a sharp cutting edge or point
	painful as if caused by a sharp instrument

sorrow (verb)	keen (verb)
feel grief	express grief verbally