vanish vs pass off

vanish and pass off both are verbs.

Word	Noun	Adjective	Verb	Adverb
vanish	No	No	Yes	No
pass off	No	No	Yes	No

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

vanish (verb)	pass off (verb)
get lost, as without warning or explanation	expel (gases or odors)
decrease rapidly and disappear	come to pass
cease to exist	disappear gradually
pass away rapidly	disregard
become invisible or unnoticeable	cause to be circulated and accepted in a false character or identity
	be accepted as something or somebody in a false character or identity