nullify

present singular third person nullifies · participle present nullifying · participle past nullified · past nullified

1. transitivelawTo make legally invalid.

   The contract has been nullified.

   3 more examples

   Near-synonyms: cancel, void, quash

   [T]hey were baffled by tears in moustached sixth-formers, by walls of impassivity in the Lower School, by silent conspiracies which nullified the rules.

   1956, Anthony Burgess, Time for a Tiger (The Malayan Trilogy), published 1972, page 37

   Lesbians for Justice therefore appeals to the organizers of the Michigan Womyn's Music Festival to nullify its "womyn-born-womyn only" policy, and to allow the attendance of post-operative male-to-female transsexuals at all future festivals.

   1992 May 8, Tamara Severns, “Open Letter To Michigan Festival Organizers”, in Gay Community News, page 4

   Synonyms: cancel, void, quash, annul, cancel

2. To prevent from happening.
3. To make of no use or value; to cancel out.

   It nullifies the night / from overkill

   1983, Men At Work, “Overkill”, in Cargo

   2 more examples

   The persuasion that a thing is impossible, at once nullifies endeavour, and like the Turkish "it is fate," torporises activity and exertion.

   1843, The Metropolitan - Volume 36, page 52

   Blowproof water has given the Navy the weapon it needed to fight fires with helicopters. Previously, the downwash from the rotor blades blew the foam, or whatever agent was being used, off the fire, nullifying its effect.

   1966, Popular Mechanics, volume 125, number 2, page 115