revoke vs annul

revoke is a noun but annul is not a noun.

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

As verbs, revoke and annul are synonyms defined as:

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

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

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