swoon vs black out

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

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

As verbs, black out is a hypernym of swoon; that is, black out is a word with a broader meaning than swoon:

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

Other hypernyms of swoon include pass out, zonk out.

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

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