proof

1a : 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

6a 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

8a : 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

Definition of proof

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