absent vs go away

absent is an adjective but go away is not an adjective.

Word	Noun	Adjective	Verb	Adverb
absent	No	Yes	Yes	No
go away	No	No	Yes	No

As verbs, go away is a hypernym of absent; that is, go away is a word with a broader meaning than absent:

Other hypernyms of absent include disappear, vanish.

absent (adjective)	go away (adjective)
not being in a specified place
lost in thought; showing preoccupation
nonexistent

absent (verb)	go away (verb)
stay away or leave	get lost, as without warning or explanation
	go away from a place
	move away from a place into another direction
	become invisible or unnoticeable