disappearance vs departure

disappearance and departure both are nouns.

Word	Noun	Adjective	Verb	Adverb
disappearance	Yes	No	No	No
departure	Yes	No	No	No

As nouns, departure is a hypernym of disappearance; that is, departure is a word with a broader meaning than disappearance:

Other hypernyms of disappearance include going, going away, leaving.

disappearance (noun)	departure (noun)
the act of leaving secretly or without explanation	the act of departing
gradually ceasing to be visible	euphemistic expressions for death
the event of passing out of sight	a variation that deviates from the standard or norm
ceasing to exist