keen vs requiem

keen and requiem both are nouns.

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

As nouns, requiem is a hypernym of keen; that is, requiem is a word with a broader meaning than keen:

keen: a funeral lament sung with loud wailing
requiem: a song or hymn of mourning composed or performed as a memorial to a dead person

Other hypernyms of keen include coronach, dirge, lament, threnody.

keen (noun)	requiem (noun)
a funeral lament sung with loud wailing	a song or hymn of mourning composed or performed as a memorial to a dead person

keen (adjective)	requiem (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)	requiem (verb)
express grief verbally