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 reasoning2obsolete : experience3: something that induces certainty or establishes validity4archaic : the quality or state of having been tested or tried ; especially : unyielding hardness5: evidence operating to determine the finding or judgment of a tribunal6 aplural 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 negative7: a test applied to articles or substances to determine whether they are of standard or satisfactory quality8 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>