darken vs blind

darken is not a noun while blind is a noun.

Word	Noun	Adjective	Verb	Adverb
darken	No	No	Yes	No
blind	Yes	Yes	Yes	No

As verbs, blind is a hyponym of darken; that is, blind is a word with a more specific, narrower meaning than darken:

Other hyponyms of darken include embrown, murk, dun, dim, dim, bedim, benight, shade, shade off, shadow, cloud, overcast.

darken (noun)	blind (noun)
	a protective covering that keeps things out or hinders sight
	a hiding place sometimes used by hunters (especially duck hunters)
	something intended to misrepresent the true nature of an activity
	people who have severe visual impairments, considered as a group

darken (adjective)	blind (adjective)
	unable to see
	not based on reason or evidence
	unable or unwilling to perceive or understand

darken (verb)	blind (verb)
become dark or darker	make dim by comparison or conceal
make dark or darker	make blind by putting the eyes out
tarnish or stain	render unable to see