Main Entry: ¹proof

Pronunciation: \ˈprüf\

Function: noun

Etymology: Middle English prof, prove, alteration of preve, from Anglo-French preove, from Late Latin proba, from Latin probare to prove — more at prove

Date: 13th century

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 especially by derivation from other statements in accordance with principles of reasoning
2 obsolete : experience
3 : something that induces certainty or establishes validity
4 archaic : the quality or state of having been tested or tried; especially : unyielding hardness
5 : evidence operating to determine the finding or judgment of a tribunal
6 a plural 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; specifically : alcoholic strength indicated by a number that is twice the percent by volume of alcohol present <whiskey of 90 proof is 45 percent alcohol>