[proof] n [ME, alter. of preove, fr. OF preuve, fr. LL proba, fr. L probare to prove--more at prove] (13c) 1 a: the cogency of evidence that compels acceptance by the mind of a truth or a fact b: the process or an instance of establishing the validity of a statement esp. by derivation from other statements in accordance with principles of reasoning
2. obs: experience
3: something that induces certainty or establishes validity
4. archaic: the quality or state of having been tested or tried; esp: unyielding hardness
5: evidence operating to determine the finding or judgment of a tribunal
6. a pl proofs or proof : a copy (as of typeset text) made for examination or correction b: a test impression of an engraving, etching, or lithograph c: a coin that is struck from a highly-polished die on a polished planchet, is not intended for circulation, and sometimes differs in metallic content from coins of identical design struck for circulation d: a test photographic print made from a negative 7: a test applied to articles or substances to determine whether they are of standard or satisfactory quality
8. a: the minimum alcoholic strength of proof spirit b: strength with reference to the standard for proof spirit; specif: alcoholic strength indicated by a number that is twice the percent by volume of alcohol present "whiskey of 90 ~ is 45% alcohol"
[2]proof adj (1592) 1: able to resist or repel "boots that were ... ~ against cold and wet --Robertson Davies"--often used in combination "windproof"
2: used in proving or testing or as a standard of comparison
3: of standard strength or quality or alcoholic content [3]proof vt (1745) 1 a: to make or take a proof or test of b: proofread
2: to give a resistant quality to
3: to activate (yeast) by mixing with water and sometimes sugar or milk -- proof.er n