Definition of proof

• n. - Any effort, process, or operation designed to establish or discover a fact or truth; an act of testing; a test; a trial.
• n. - That degree of evidence which convinces the mind of any truth or fact, and produces belief; a test by facts or arguments that induce, or tend to induce, certainty of the judgment; conclusive evidence; demonstration.
• n. - The quality or state of having been proved or tried; firmness or hardness that resists impression, or does not yield to force; impenetrability of physical bodies.
• n. - Firmness of mind; stability not to be shaken.
• n. - A trial impression, as from type, taken for correction or examination; -- called also proof sheet.
• n. - A process for testing the accuracy of an operation performed. Cf. Prove, v. t., 5.
• v. t. - Armor of excellent or tried quality, and deemed impenetrable; properly, armor of proof.
• a. - Used in proving or testing; as, a proof load, or proof charge.
• a. - Firm or successful in resisting; as, proof against harm; waterproof; bombproof.
• a. - Being of a certain standard as to strength; -- said of alcoholic liquors.