from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The evidence or argument that compels the mind to accept an assertion as true.
  • noun The validation of a proposition by application of specified rules, as of induction or deduction, to assumptions, axioms, and sequentially derived conclusions.
  • noun A statement or argument used in such a validation.
  • noun Convincing or persuasive demonstration.
  • noun The state of being convinced or persuaded by consideration of evidence.
  • noun Determination of the quality of something by testing; trial.
  • noun The establishment of the truth or falsity of an allegation by evidence.
  • noun The evidence offered in support of or in contravention of an allegation.
  • noun The alcoholic strength of a liquor, expressed by a number that is twice the percentage by volume of alcohol present.
  • noun A trial sheet of printed material that is made to be checked and corrected.
  • noun A trial impression of a plate, stone, or block taken at any of various stages in engraving.
  • noun A trial photographic print.
  • noun Any of a limited number of newly minted coins or medals struck as specimens and for collectors from a new die on a polished planchet.
  • noun Archaic Proven impenetrability.
  • adjective Fully or successfully resistant; impervious. Often used in combination.
  • adjective Of standard alcoholic strength.
  • adjective Used to proofread or correct typeset copy.
  • intransitive verb To make a trial impression of (printed or engraved matter).
  • intransitive verb To proofread (copy).
  • intransitive verb To activate (dormant dry yeast) by adding water.
  • intransitive verb To work (dough) into proper lightness.
  • intransitive verb To treat so as to make resistant.
  • intransitive verb Printing To proofread.
  • intransitive verb To become properly light for cooking.

from The Century Dictionary.

  • noun An assay of a bullion of known composition placed in the muffle with the other assays in order to determine the difference in weight due to the loss of silver by volatilization and absorption by the cupel.
  • noun In photography, a trial print from a negative.
  • noun Any effort, act, or operation made for the purpose of ascertaining any truth or fact; a test; a trial: as, to make proof of a person's trustworthiness or courage.
  • noun Evidence and argumentation putting the conclusion beyond reasonable doubt; demonstration, perfect or imperfect.
  • noun A thing proved or tried; truth or knowledge gathered by experience; experience.
  • noun The state of having been tested and approved; firmness, hardness, or impenetrability: specifically applied to arms or armor of defense, to note that they have been duly tested and are impenetrable.
  • noun In law: The convincing effect of evidence; the manifestation of the truth of a proposition by presenting the reasons for assenting to it; such an array of evidence as should determine the judgment of the tribunal in regard to a matter of fact.
  • noun plural In equity practice, the instruments of evidence in their documentary form, as depositions, deeds, etc., received in a cause.
  • noun The presentation of sufficient evidence: as, the burden of proof lies with the plaintiff.
  • noun In Scots law, the taking of evidence by a judge upon an issue framed in pleading.
  • noun A test applied to manufactured articles or to natural substances prepared for use; hence, the state of that which has undergone this test, or is capable of undergoing it satisfactorily. Compare armor of proof.
  • noun 7. In alcoholic liquors, the degree of strength which gives a specific gravity of 0.920. See II., 2.
  • noun In printing, a trial impression from composed type, taken for correction.
  • noun In engraving and etching, an impression taken from an engraved plate to show its state during the progress of executing it; also, an early and superior impression, or one of a limited number, taken before the title or inscription is engraved on the plate, and known as proof before letter.
  • noun In numismatics, any early impression struck at the mint from a coin-die used for producing the current coins of the realm.
  • noun In bookbinding, the rough uncut edges of the shorter leaves of a trimmed book, which prove that the book has not been cut down too much.
  • noun In arithmetic, an operation serving to check the accuracy of the calculation.
  • noun Proof independent of experience.


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English prove, preve, from Anglo-Norman prove and from Old French prueve, both from Late Latin proba, from Latin probāre, to prove; see prove.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Middle English proof, from Old French prove, from Late Latin proba ("a proof"), from Latin probare ("to prove"); see prove.


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  • A multitude of words is no proof of a prudent mind.

    Thales (635 BC - 543 BC)

    December 8, 2006

  • Well that's all of us told, isn't it?

    October 3, 2007

  • *hangs head*

    October 3, 2007

  • So that's what holds jennarenn back... ;-)

    October 3, 2007

  • A very prudent person. :-)

    October 3, 2007

  • It's prudent to pull a number of proofs before printing an edition.

    July 8, 2008

  • Precisely.

    July 9, 2008

  • You're right, especially in large math books. Leave them wanting more for the next edition.

    July 9, 2008

  • It's often useful to assume that people reading your message do not believe what you're telling them. It may not be the case for all of them but it's likely that a good proportion are skeptical. Offer proof wherever you can.

    '15 words that will make you money'

    July 23, 2009