void vs annul

void is a noun but annul is not a noun.

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

As verbs, void and annul are synonyms defined as:

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

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

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

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