overpower vs knock out

overpower and knock out both are verbs.

Word	Noun	Adjective	Verb	Adverb
overpower	No	No	Yes	No
knock out	No	No	Yes	No

As verbs, knock out is a hyponym of overpower; that is, knock out is a word with a more specific, narrower meaning than overpower:

Other hyponyms of overpower include devastate, clutch, get hold of, seize, kill, benight, stagger, lock.

overpower (verb)	knock out (verb)
overcome by superior force	destroy or break forcefully
overcome, as with emotions or perceptual stimuli	eliminate
	empty (as of tobacco) by knocking out
	knock unconscious or senseless
	overwhelm with admiration