Synonyms/Hypernyms (Ordered by Estimated Frequency) of verb annul

2 senses of annul

Sense 1
invalidate, annul, quash, void, avoid, nullify -- (declare invalid; "The contract was annulled"; "void a plea")
       => cancel, strike down -- (declare null and void; make ineffective; "Cancel the election results"; "strike down a law")

Sense 2
revoke, annul, lift, countermand, reverse, repeal, overturn, rescind, vacate -- (cancel officially; "He revoked the ban on smoking"; "lift an embargo"; "vacate a death sentence")
       => cancel, strike down -- (declare null and void; make ineffective; "Cancel the election results"; "strike down a law")