Nullify \Nul"li*fy\, v. t. [imp. & p. p. {Nullified}; p. pr. & vb. n. {Nullifying}.] [L. nullificare; nullus none + -ficare (in comp.) to make. See {Null}, a., and {-fy}.] To make void; to render invalid; to deprive of legal force or efficacy. Such correspondence would at once nullify the conditions of the probationary system. --I. Taylor. Syn: To abrogate; revoke; annul; repeal; invalidate; cancel. See {Abolish}.