Vitiate

·vt To cause to fail of effect, either wholly or in part; to make void; to destroy, as the validity or binding force of an instrument or transaction; to Annul; as, any undue influence exerted on a jury vitiates their verdict; fraud vitiates a contract.

II. Vitiate ·vt To make vicious, faulty, or imperfect; to render defective; to injure the substance or qualities of; to Impair; to Contaminate; to Spoil; as, exaggeration vitiates a style of writing; sewer gas vitiates the air.