proof / proōf/ • n. 1. evidence or argument establishing or helping to establish a fact or the truth of a statement: you will be asked to give proof of your identity| this is not a proof for the existence of God. ∎  Law the spoken or written evidence in a trial. ∎  the action or process of establishing the truth of a statement: it shifts the onus of proof in convictions from the police to the public. ∎ archaic a test or trial. ∎  a series of stages in the resolution of a mathematical or philosophical problem.2. a trial print of something, in particular: ∎  Printing a trial impression of a page, taken from type or film and used for making corrections before final printing. ∎  a trial photographic print made for initial selection. ∎  each of a number of impressions from an engraved plate, esp. (in commercial printing) of a limited number before the ordinary issue is printed and before an inscription or signature is added. ∎  any of various preliminary impressions of coins struck as specimens.3. the strength of distilled alcoholic liquor, relative to proof spirit taken as a standard of 100: [in comb.] powerful 132-proof rum. • adj. 1. able to withstand something damaging; resistant: the marine battle armor was proof against most weapons| [in comb.] the system comes with idiot-proof instructions. 2. denoting a trial impression of a page or printed work: a proof copy is sent up for checking.• v. [tr.] 1. make (fabric) waterproof: [as adj.] (proofed) the tent is made from proofed nylon. 2. make a proof of (a printed work, engraving, etc.): [as n.] (proofing) proofing could be done on a low-cost printer. ∎  proofread (a text): a book about dinosaurs was being proofed by the publisher.3. activate (yeast) by the addition of liquid. ∎  knead (dough) until light and smooth. ∎  [intr.] (of dough) prove: shape into a baguette and let proof for a few minutes.