quash vs annul

quash and annul both are verbs.

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

As verbs, quash and annul are synonyms defined as:

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

quash (verb)	annul (verb)
put down by force or intimidation	cancel officially
declare invalid	declare invalid