cracking vs keen

cracking and keen both are nouns.

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

As adjectives, cracking and keen are synonyms defined as:

Other synonyms of cracking include bang-up, bully, corking, dandy, great, groovy, neat, nifty, not bad, old, peachy, slap-up, smashing, swell.

cracking (noun)	keen (noun)
the act of cracking something	a funeral lament sung with loud wailing
a sudden sharp noise
the process whereby heavy molecules of naphtha or petroleum are broken down into hydrocarbons of lower molecular weight (especially in the oil-refining process)

cracking (adjective)	keen (adjective)
excellent	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

cracking (verb)	keen (verb)
	express grief verbally