keen vs sorrow

keen and sorrow both are nouns.

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

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

keen (adjective)	sorrow (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

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