[ proof ]
See synonyms for: proofprooferproofest on

  1. evidence sufficient to establish a thing as true, or to produce belief in its truth.

  2. anything serving as such evidence: What proof do you have?

  1. the act of testing or making trial of anything; test; trial: to put a thing to the proof.

  2. the establishment of the truth of anything; demonstration.

  3. Law. (in judicial proceedings) evidence having probative weight.

  4. the effect of evidence in convincing the mind.

  5. an arithmetical operation serving to check the correctness of a calculation.

  6. Mathematics, Logic. a sequence of steps, statements, or demonstrations that leads to a valid conclusion.

  7. a test to determine the quality, durability, etc., of materials used in manufacture.

  8. Distilling.

    • the arbitrary standard strength, as of an alcoholic liquor.

    • strength with reference to this standard: “100 proof” signifies aproof spirit, usually 50% alcohol.

  9. Photography. a trial print from a negative.

  10. Printing.

    • a trial impression, as of composed type, taken to correct errors and make alterations.

    • one of a number of early and superior impressions taken before the printing of the ordinary issue: to pull a proof.

  11. (in printmaking) an impression taken from a plate or the like to show the quality or condition of work during the process of execution; a print pulled for examination while working on a plate, block, stone, etc.

  12. Numismatics. one of a limited number of coins of a new issue struck from polished dies on a blank having a polished or matte surface.

  13. the state of having been tested and approved.

  14. proved strength, as of armor.

  15. Scots Law. the trial of a case by a judge alone, without a jury.

  1. able to withstand; successful in not being overcome: proof against temptation.

  2. impenetrable, impervious, or invulnerable: proof against outside temperature changes.

  1. used for testing or proving; serving as proof.

  2. of standard strength, as an alcoholic liquor.

  3. of tested or proven strength or quality: proof armor.

  4. noting pieces of pure gold and silver that the U.S. assay and mint offices use as standards.

verb (used with object)
  1. to test; examine for flaws, errors, etc.; check against a standard or standards.

  2. Printing. prove (def. 7).

  1. to proofread.

  2. to treat or coat for the purpose of rendering resistant to deterioration, damage, etc. (often used in combination): to proof a house against termites; to shrink-proof a shirt.

  3. Cooking.

    • to test the effectiveness of (yeast), as by combining with warm water so that a bubbling action occurs.

    • to cause (especially bread dough) to rise due to the addition of baker's yeast or other leavening.

Origin of proof

First recorded in 1175–1225; Middle English prove, prooff, prof, proufe, alteration (by association with the vowel of prove) of preove, proeve, prieve, pref, from Middle French preve, proeve, prueve, from Late Latin proba “a test,” akin to Latin probāre “to test and find good”; cf. pree

synonym study For proof

1. See evidence.

word story For proof

Proof entered English in the 12th century as Middle English prove, prooff, prof, proufe, with the meaning “evidence sufficient to establish a thing as true.” It finds its roots in Late Latin proba, meaning "a test." An example of proof meaning “test” is in the English proverb “All the proof of a pudding is in the eating,” first recorded in English in 1605. The proverb is popularly but wrongly attributed to Miguel Cervantes. In the second part of Cervantes’ Don Quixote (published in 1615), Cervantes wrote “Por la muestra se conoce el paño,” literally, “From the sample you know the cloth,” which was translated into English as “The proof of a pudding is in the eating” by Peter Anthony Motteux, a French-born English playwright and translator, in his English translation (third edition 1712). We know this today as the saying “The proof is in the pudding.”

Other words for proof

Other words from proof

  • re-proof, verb (used with object)
  • un·proofed, adjective

Words Nearby proof

Other definitions for -proof (2 of 2)


  1. a combining form meaning “resistant, impervious to” that specified by the initial element: burglarproof; childproof; waterproof. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use proof in a sentence

British Dictionary definitions for proof (1 of 2)


/ (pruːf) /

  1. any evidence that establishes or helps to establish the truth, validity, quality, etc, of something

  2. law the whole body of evidence upon which the verdict of a court is based

  1. maths logic a sequence of steps or statements that establishes the truth of a proposition: See also direct (def. 17), induction (def. 4), induction (def. 8)

  2. the act of testing the truth of something (esp in the phrase put to the proof)

  3. Scots law trial before a judge without a jury

  4. printing a trial impression made from composed type, or a print-out (from a laser printer, etc) for the correction of errors

  5. (in engraving, etc) a print made by an artist or under his supervision for his own satisfaction before he hands the plate over to a professional printer

  6. photog a trial print from a negative

    • the alcoholic strength of proof spirit

    • the strength of a beverage or other alcoholic liquor as measured on a scale in which the strength of proof spirit is 100 degrees

  1. (usually postpositive foll by against) able to resist; impervious (to): the roof is proof against rain

  2. having the alcoholic strength of proof spirit

  1. of proved strength or impenetrability: proof armour

  1. (tr) to take a proof from (type matter, a plate, etc)

  2. to proofread (text) or inspect (a print, etc), as for approval

  1. to render (something) proof, esp to waterproof

Origin of proof

C13: from Old French preuve a test, from Late Latin proba, from Latin probāre to test

British Dictionary definitions for -proof (2 of 2)


adjective, combining form
  1. secure against (damage by); (make) impervious to: waterproof; mothproof; childproof

Origin of -proof

from proof (adj)

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for proof


[ prōōf ]

  1. A demonstration of the truth of a mathematical or logical statement, based on axioms and theorems derived from those axioms.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.