black out vs pass out

black out and pass out both are verbs.

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

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

black out and pass out: lose consciousness due to a sudden trauma, for example

Other synonyms of black out include zonk out.

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

black out: lose consciousness due to a sudden trauma, for example
pass out: 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, swoon.

black out (verb)	pass out (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	lose consciousness due to a sudden trauma, for example
darken completely	give to several people