discover vs witness

discover is not a noun while witness is a noun.

Word	Noun	Adjective	Verb	Adverb
discover	No	No	Yes	No
witness	Yes	No	Yes	No

discover (noun)	witness (noun)
	testimony by word or deed to your religious faith
	someone who sees an event and reports what happened
	a close observer; someone who looks at something (such as an exhibition of some kind)
	(law) a person who attests to the genuineness of a document or signature by adding their own signature
	(law) a person who testifies under oath in a court of law

discover (verb)	witness (verb)
get to know or become aware of, usually accidentally	be a witness to
identify as in botany or biology, for example	perceive or be contemporaneous with
make known to the public information that was previously known only to a few people or that was meant to be kept a secret
make a discovery, make a new finding
see for the first time; make a discovery
discover or determine the existence, presence, or fact of by perception with the eyes
find unexpectedly