swoon vs pass out

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

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

As verbs, swoon and pass out are synonyms defined as:

swoon and pass out: pass out from weakness, physical or emotional distress due to a loss of blood supply to the brain

Other synonyms of swoon include conk, faint.

As verbs, pass out is a hypernym of swoon; that is, pass 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
pass out: lose consciousness due to a sudden trauma, for example

Other hypernyms of swoon include black out, zonk out.

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

swoon (verb)	pass out (verb)
pass out from weakness, physical or emotional distress due to a loss of blood supply to the brain	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
	give to several people