annul vs void

annul is not a noun while void is a noun.

Word	Noun	Adjective	Verb	Adverb
annul	No	No	Yes	No
void	Yes	Yes	Yes	No

As verbs, annul and void are synonyms defined as:

Other synonyms of annul include avoid, invalidate, nullify, quash.

annul (noun)	void (noun)
	an empty area or space
	the state of nonexistence

annul (adjective)	void (adjective)
	containing nothing
	lacking any legal or binding force

annul (verb)	void (verb)
cancel officially	excrete or discharge from the body
declare invalid	take away the legal force of or render ineffective
	clear (a room, house, place) of occupants or empty or clear (a place or receptacle) of something
	declare invalid