come about vs pass off

come about and pass off both are verbs.

Word	Noun	Adjective	Verb	Adverb
come about	No	No	Yes	No
pass off	No	No	Yes	No

As verbs, come about and pass off are synonyms defined as:

Other synonyms of come about include fall out, go on, hap, happen, occur, pass, take place.

come about (verb)	pass off (verb)
come to pass	expel (gases or odors)
	come to pass
	disappear gradually
	disregard
	cause to be circulated and accepted in a false character or identity
	be accepted as something or somebody in a false character or identity