black out vs swoon

black out is not a noun while swoon is a noun.

Word	Noun	Adjective	Verb	Adverb
black out	No	No	Yes	No
swoon	Yes	No	Yes	No

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

black out: lose consciousness due to a sudden trauma, for example
swoon: pass out from weakness, physical or emotional distress due to a loss of blood supply to the brain

Other hyponyms of black out include conk, faint, pass out.

black out (noun)	swoon (noun)
	a spontaneous loss of consciousness caused by insufficient blood to the brain

black out (verb)	swoon (verb)
lose consciousness due to a sudden trauma, for example	pass out from weakness, physical or emotional distress due to a loss of blood supply to the brain
suppress by censorship as for political reasons
darken completely