pass off vs come about

pass off and come about both are verbs.

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

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

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

pass off (verb)	come about (verb)
expel (gases or odors)	come to pass
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