Evidence or argument establishing a fact or the truth of a statement. The lawyer presented proof of the defendant's innocence.
A trial impression of a page, taken from type or film and used for making corrections before final printing. The editor reviewed the proof to ensure there were no errors before the book went to print.
A test or trial of something to establish its quality, performance, or reliability. The prototype underwent exhaustive proof before the product launch.
A measure of the strength of an alcoholic beverage, expressed as twice the percentage of alcohol present. The whiskey was labeled as 80 proof, indicating it contained 40% alcohol.
(mathematics, logic) A sequence of logical deductions establishing the truth of a theorem or proposition. The professor sketched a proof of the theorem on the board.