Definition of proof in English:



  • 1[mass noun] Evidence or argument establishing a fact or the truth of a statement.

    ‘you will be asked to give proof of your identity’
    [count noun] ‘this is not a proof for the existence of God’
    • ‘You will need proof of your identity and the address where you are living on election day.’
    • ‘They are based on the false assumption that the substantive offence requires proof of a fact that life is endangered.’
    • ‘Many atheists demand a scientific proof for the existence of God.’
    • ‘The author finally attempts to provide conclusive proof of Germany's decline in chapter 7.’
    • ‘His silence is a matter which is neutral in terms of providing positive proof of his guilt.’
    • ‘Therefore, a total ban on private use of the lagoon requires concrete scientific proof of negative influences.’
    • ‘It is too easy to find fault, to point a finger, without any facts or proof.’
    • ‘That statement is proof of my existence, for how can you make nothing?’
    • ‘Always check the seller's identity by asking for proof of name and address and be wary of sellers who want to meet you anywhere other than their home.’
    • ‘One of the most important properties I'm interested in when I'm looking for arguments or evidence or proofs or persuasive cases is strength and the ability to bear a lot of weight.’
    • ‘The critics will point to this as irrefutable proof of their argument that vouchers undermine the public school system.’
    • ‘A little while later he emailed me with irrefutable proof of my guilt.’
    • ‘No story describing a problem or social phenomenon was complete without a few meaningless statistics passed off as hard fact or proof of some assertion.’
    • ‘The numbers themselves do not constitute definitive proof.’
    • ‘The government had no definitive proof of ownership, so therefore everyone was guilty.’
    • ‘That's completely absurd and there's no proof to validate that statement.’
    • ‘There was, after all, too much proof to the contrary.’
    • ‘However, these customers would also have to provide documentary proof of their claims.’
    • ‘A retrospective glance at the 2000-2001 regular season offers ample proof of blatant mismatches.’
    • ‘If there is a variation, you may need to supply proof of identity.’
    evidence, verification, corroboration, authentication, confirmation, certification, validation, attestation, demonstration, substantiation, witness, testament
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    1. 1.1Law The spoken or written evidence in a trial.
      • ‘The laws of evidence and proof are aimed at establishing beyond a doubt which individual is guilty.’
      • ‘Until the evidentiary threshold of proof beyond a reasonable doubt is reached, the judge and the Constitution order the jury to acquit.’
      • ‘Counsel set out parts of the appellant's proof of evidence available at the trial.’
      • ‘The burden of proof on the balance of probabilities lies on the defendant.’
      • ‘In a criminal case you need to have proof beyond a reasonable doubt.’
    2. 1.2The action of establishing the truth of a statement.
      ‘spatial dimensions whose very existence is beyond all hope of proof’
      • ‘As a result, it seemed to them that the objectivity of scientific knowledge was no longer capable of proof.’
    3. 1.3[count noun]A series of stages in the resolution of a mathematical or philosophical problem.
      • ‘An argument becomes a proof when the mathematical community agrees it is such.’
      • ‘I shall carry out such a consistency proof for elementary number theory.’
      • ‘This faith in the indubitable certainty of mathematical proofs was sadly shaken around 1900 by the discovery of the antinomies or paradoxes of set theory.’
      • ‘Euclid changed the proofs of several theorems in this book so that they fitted the new definition of proportion given by Eudoxus.’
      • ‘So, in the absence of a mathematical proof deciding this question, none of us has any a priori knowledge about this question in either direction.’
      • ‘How many proofs do mathematicians publish each year?’
      • ‘From such a viewpoint, it would seem possible to arrange mathematical proofs into strata characterized by their degree of simplicity.’
      • ‘For example, in proofs about sets, Venn diagrams provided a useful part of a concept image in some cases.’
      • ‘Mathematicians later found proofs for other special cases.’
      • ‘The only thing that's missing is perhaps a very solid idea of what it means to do a mathematical proof.’
      • ‘On the other hand he had only a vague idea of what constitutes a mathematical proof.’
      • ‘His main work involved applying philosophy to mathematics, the philosophy taking precedence over rigorous mathematical proofs.’
      • ‘Fermat subsequently died, leaving mathematicians to search for 350 years for a proof of the theorem.’
      • ‘It gives a proof that every whole number has a Fibonacci number for which it is a factor.’
      • ‘We wish to expound in detail some of the many proofs of this theorem.’
      • ‘Nguyen's work is one manifestation of her longstanding love for rigorous and creative mathematical proofs.’
      • ‘Mathematical proofs of conjectures, however, require more than overwhelming numerical evidence.’
      • ‘In a nutshell, it asks for the simplest proof of any theorem.’
      • ‘His publications include a biography of Leonhard Euler and a booklet on mathematical proofs.’
      • ‘The proof of this theorem makes essential use of free choice sequences.’
  • 2Printing
    A trial impression of a page, taken from type or film and used for making corrections before final printing.

    • ‘I was scheduled to spend much of the day correcting the final proofs of my forthcoming biography, Nehru: The Invention of India.’
    • ‘Stuart had completed all of his editing and writing for volume 7 before his death and was looking forward to reading the final proofs.’
    • ‘I had before me a stack of final proofs to approve, but under the circumstances it was nearly impossible to read them; every word seemed trivial in comparison to the horrific tragedy.’
    • ‘I turned the pages and noted all the red correction marks on my proofs, cradling my pounding head in my hands.’
    • ‘Their intention has been to wait for the final proofs of their articles before correcting the intentional misstatements.’
    page proof, galley proof, galley, pull, slip, trial print
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    1. 2.1A trial photographic print made for initial selection.
      • ‘About 6000 of Robert's negatives and picture proofs are held by the Alexander Turnbull Library in Wellington.’
      • ‘The trial proofs were rejected, and the finished photographs never made.’
      • ‘I found your article on the value of so-called artist's proofs extremely interesting.’
      • ‘Artist's proofs can be numbered, but often they are not.’
    2. 2.2Each of a number of impressions from an engraved plate, especially (in commercial printing) of a limited number before the ordinary issue is printed and before an inscription or signature is added.
      • ‘He owned eight paintings and fourteen drawings, nine etchings on Japanese paper, fifty-nine separate proofs and an almost complete set of his prints.’
      • ‘Dürer published quite large numbers of his woodcut series in proofs before text on the reverse of the sheet.’
      • ‘Sometimes artist's proofs are used to hide the real number of an edition.’
      • ‘Oscar Marshall may also have offered a limited number of hand-signed proofs.’
      • ‘This exhibition - including so many large prints, so many of their proofs and their matrices - demands a lot of wall space.’
    3. 2.3A specially struck specimen coin with a polished or frosted finish.
  • 3[mass noun] The strength of distilled alcoholic spirits, relative to proof spirit taken as a standard of 100.

    [in combination] ‘powerful 132-proof rum’
    • ‘Your liver processes alcohol out of your system at an average rate of about 1.5 ounces of 80 proof alcohol an hour.’
    • ‘This hand-selected whiskey was bottled at 94 proof in elegantly sculpted decanters.’
    • ‘Before aging, bourbon's proof must be lowered to no higher than 125 proof using distilled water.’
  • 4A test or trial of something.

    criterion, indication, yardstick, touchstone, standard, measure, litmus test, barometer
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  • 5Scots Law
    A trial or a civil case before a judge without a jury.


  • 1Able to withstand something damaging; resistant.

    ‘the marine battle armour was proof against most weapons’
    [in combination] ‘the system comes with idiot-proof instructions’
    • ‘Work has protected wildlife along the route, including measures to keep a colony of protected great crested newts safe, badger tunnels and deer-proof fencing.’
    • ‘Beat the mixture lightly and pour it into individual oven-proof pots.’
    • ‘We need proper sanitation and proper rat-proof construction.’
    • ‘Inclinations towards freedom, however, are not proof against systematic countermeasures.’
    • ‘Maybe it's just as well that we have these idiot-proof tills, because without them the numerically challenged would be all but unemployable and we'd have to support them through a lifetime on the dole.’
    • ‘She explained that 12 staff joined colleagues from across the county to update their training in the use of the chemical-proof suits.’
    resistant, impenetrable, impervious, repellent
    proofed, treated
    waterproof, windproof, rainproof, leakproof, damp-proof, weatherproof, bulletproof, bombproof, fireproof, soundproof, childproof, tamper-proof
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  • 2Denoting a trial impression of a page or printed work.

    ‘a proof copy is sent up for checking’
    • ‘I am always impressed with accurate proof reading.’
    • ‘Next came the bound proof copies, incorporating quite long extracts from these letters.’
    • ‘Then a set of proof prints is sent to the artist to review.’
    • ‘No, I don't mind people buying proof copies, but I'd advise against buying them to collect.’
    • ‘The following categories of nationalistic blessing and their proof texts indicate they do.’
    • ‘Accompanying the CD-R is a set of proof pages that the printer can use to make sure that the magazine that is being printed matches the sample pages.’
    • ‘Then the printer stepped in, rubbed ink on the raised lines and made several proof copies from the relief block.’
    • ‘Keynes was asked to comment on the proof copy of the work.’
    • ‘Students helped enter more than 800,000 entries, and helped with proof reading.’
    • ‘Having been sent an early proof copy, I have already been using it for some months.’
    • ‘I read this short novel a few months ago, in a proof copy, knowing nothing about the author.’
    • ‘You know, I don't really mind people selling proof copies on e-bay.’
    • ‘A proof print is an example taken when the work is incomplete or not ready for publication.’
    • ‘I am continuing to work on my book, proof reading and such.’


  • 1Make (fabric) waterproof.

    ‘the flysheet is made from proofed nylon’
    • ‘You can spray the line with silicone line float (or I use the silicone sprays used for proofing nylon tents).’
  • 2Make a proof of (a printed work, engraving, etc.)

    ‘proofing could be done on a low-cost printer’
    • ‘When their concepts were finalized, students made a working model by proofing their work in black and white on the artroom's laser printer.’
    • ‘As they become available from Weblications, the company scanning and proofing them, they will be put up for readers to consult.’
    • ‘So sketches were sketched, proofs were proofed, copies were bound.’
    set in print, send to press, run off, preprint, reprint, pull, proof, copy, reproduce
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    1. 2.1Proofread (a text)
      ‘William proofed much of her work’
      • ‘I don't even know what the job is, but I'll proof milk cartons at this point.’
      • ‘Her mother was already at the table proofing the documents she would need that day for her board meeting.’
      • ‘She also has had all contact with authors, edited and tagged the journal pages, and proofed them.’
      • ‘He was asking me to proof something I'd already proofed, saying they'd made more changes.’
      • ‘Vitally, this interval permitted the whole paper to be proofed before printing.’
      • ‘Together we evolved a monthly theme, subbed, rewrote and proofed the magazine.’
      • ‘If you are not the best at proofing your own documents, have an eagle-eyed assistant or colleague on hand to review them for you.’
      • ‘Please also keep in mind that my beta reader hasn't proofed this yet.’
  • 3North American Activate (yeast) by the addition of liquid.

    ‘proof the yeast with the teaspoon of sugar’
    • ‘This morning's recipe was the first he'd found that called for proofing the yeast with warm water and sugar; previous methods had called, somewhat illogically, for the yeast to be added dry to the flour.’
    1. 3.1Knead (dough) until light and smooth.
    2. 3.2[no object](of dough) prove.
      ‘shape into a baguette and let proof for a few minutes’
      • ‘If you're proofing at higher temperatures, your dough will rise faster, so you'll need to keep an eye on it.’
      • ‘Brush lightly with egg wash, cover with a damp cloth, and set aside to proof until double in volume, about 30 minutes.’


Middle English preve, from Old French proeve, from late Latin proba, from Latin probare to test, prove. The change of vowel in late Middle English was due to the influence of prove. Current senses of the verb date from the late 19th century.