TKO vs kayo

TKO and kayo both are nouns.

Word	Noun	Adjective	Verb	Adverb
TKO	Yes	No	No	No
kayo	Yes	No	Yes	No

As nouns, kayo is a hypernym of TKO; that is, kayo is a word with a broader meaning than TKO:

TKO: a knockout declared by the referee who judges one boxer unable to continue
kayo: a blow that renders the opponent unconscious

Other hypernyms of TKO include knockout, KO.

TKO (noun)	kayo (noun)
a knockout declared by the referee who judges one boxer unable to continue	a blow that renders the opponent unconscious

TKO (verb)	kayo (verb)
	knock unconscious or senseless