fall off vs vanish

fall off and vanish both are verbs.

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

As verbs, vanish is a hypernym of fall off; that is, vanish is a word with a broader meaning than fall off:

Other hypernyms of fall off include disappear, go away.

fall off (verb)	vanish (verb)
fall heavily or suddenly; decline markedly	get lost, as without warning or explanation
diminish in size or intensity	decrease rapidly and disappear
come off	cease to exist
	pass away rapidly
	become invisible or unnoticeable