annul vs revoke

annul is not a noun while revoke is a noun.

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

As verbs, annul and revoke are synonyms defined as:

Other synonyms of annul include countermand, lift, overturn, repeal, rescind, reverse, vacate.

annul (noun)	revoke (noun)
	the mistake of not following suit when able to do so

annul (verb)	revoke (verb)
cancel officially	cancel officially
declare invalid	fail to follow suit when able and required to do so