Nul'li·fy transitive verb [ imperfect & past participle Nullified ; present participle & verbal noun Nullifying .] [ Latin nullificare ; nullus none + -ficare (in comp.) to make. See Null , 
verb make ineffective by counterbalancing the effect of; `Her optimism neutralizes his gloom`; `This action will negate the effect of my efforts`
• (a.) To make void; to render invalid; to deprive of legal force or efficacy. • (a.) To make void; to render invalid; to deprive of legal force or efficacy.
declare invalid
declare invalid