strike down vs poleaxe

strike down is not a noun while poleaxe is a noun.

Word	Noun	Adjective	Verb	Adverb
strike down	No	No	Yes	No
poleaxe	Yes	No	Yes	No

As verbs, poleaxe is a hyponym of strike down; that is, poleaxe is a word with a more specific, narrower meaning than strike down:

Other hyponyms of strike down include chop down, poleax, log, lumber, cut.

strike down (noun)	poleaxe (noun)
	a battle ax used in the Middle Ages; a long handled ax and a pick
	an ax used to slaughter cattle; has a hammer opposite the blade

strike down (verb)	poleaxe (verb)
cause to fall by or as if by delivering a blow	fell with or as if with a poleax
cause to die, especially suddenly
declare null and void; make ineffective