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’
    • ‘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.’
    • ‘A retrospective glance at the 2000-2001 regular season offers ample proof of blatant mismatches.’
    • ‘The author finally attempts to provide conclusive proof of Germany's decline in chapter 7.’
    • ‘There was, after all, too much proof to the contrary.’
    • ‘If there is a variation, you may need to supply proof of identity.’
    • ‘That's completely absurd and there's no proof to validate that statement.’
    • ‘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.’
    • ‘It is too easy to find fault, to point a finger, without any facts or proof.’
    • ‘The critics will point to this as irrefutable proof of their argument that vouchers undermine the public school system.’
    • ‘Therefore, a total ban on private use of the lagoon requires concrete scientific proof of negative influences.’
    • ‘The numbers themselves do not constitute definitive proof.’
    • ‘They are based on the false assumption that the substantive offence requires proof of a fact that life is endangered.’
    • ‘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.’
    • ‘That statement is proof of my existence, for how can you make nothing?’
    • ‘The government had no definitive proof of ownership, so therefore everyone was guilty.’
    • ‘However, these customers would also have to provide documentary proof of their claims.’
    • ‘His silence is a matter which is neutral in terms of providing positive proof of his guilt.’
    • ‘Many atheists demand a scientific proof for the existence of God.’
    • ‘You will need proof of your identity and the address where you are living on election day.’
    • ‘A little while later he emailed me with irrefutable proof of my guilt.’
    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.
      • ‘Until the evidentiary threshold of proof beyond a reasonable doubt is reached, the judge and the Constitution order the jury to acquit.’
      • ‘The burden of proof on the balance of probabilities lies on the defendant.’
      • ‘The laws of evidence and proof are aimed at establishing beyond a doubt which individual is guilty.’
      • ‘Counsel set out parts of the appellant's proof of evidence available at the trial.’
      • ‘In a criminal case you need to have proof beyond a reasonable doubt.’
    2. 1.2 The 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.
      • ‘Nguyen's work is one manifestation of her longstanding love for rigorous and creative mathematical proofs.’
      • ‘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.’
      • ‘His main work involved applying philosophy to mathematics, the philosophy taking precedence over rigorous mathematical proofs.’
      • ‘I shall carry out such a consistency proof for elementary number theory.’
      • ‘The proof of this theorem makes essential use of free choice sequences.’
      • ‘His publications include a biography of Leonhard Euler and a booklet on mathematical proofs.’
      • ‘An argument becomes a proof when the mathematical community agrees it is such.’
      • ‘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.’
      • ‘On the other hand he had only a vague idea of what constitutes a mathematical proof.’
      • ‘From such a viewpoint, it would seem possible to arrange mathematical proofs into strata characterized by their degree of simplicity.’
      • ‘We wish to expound in detail some of the many proofs of this theorem.’
      • ‘Mathematical proofs of conjectures, however, require more than overwhelming numerical evidence.’
      • ‘The only thing that's missing is perhaps a very solid idea of what it means to do a mathematical proof.’
      • ‘Fermat subsequently died, leaving mathematicians to search for 350 years for a proof of the theorem.’
      • ‘How many proofs do mathematicians publish each year?’
      • ‘In a nutshell, it asks for the simplest proof of any theorem.’
      • ‘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.’
      • ‘It gives a proof that every whole number has a Fibonacci number for which it is a factor.’
  • 2Printing
    A trial impression of a page, taken from type or film and used for making corrections before final printing.

    • ‘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 was scheduled to spend much of the day correcting the final proofs of my forthcoming biography, Nehru: The Invention of India.’
    • ‘Their intention has been to wait for the final proofs of their articles before correcting the intentional misstatements.’
    • ‘I turned the pages and noted all the red correction marks on my proofs, cradling my pounding head in my hands.’
    • ‘Stuart had completed all of his editing and writing for volume 7 before his death and was looking forward to reading the final proofs.’
    page proof, galley proof, galley, pull, slip, trial print
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    1. 2.1 A trial photographic print made for initial selection.
      • ‘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.’
      • ‘About 6000 of Robert's negatives and picture proofs are held by the Alexander Turnbull Library in Wellington.’
      • ‘Artist's proofs can be numbered, but often they are not.’
    2. 2.2 Each 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.
      • ‘Oscar Marshall may also have offered a limited number of hand-signed proofs.’
      • ‘Dürer published quite large numbers of his woodcut series in proofs before text on the reverse of the sheet.’
      • ‘This exhibition - including so many large prints, so many of their proofs and their matrices - demands a lot of wall space.’
      • ‘Sometimes artist's proofs are used to hide the real number of an edition.’
      • ‘He owned eight paintings and fourteen drawings, nine etchings on Japanese paper, fifty-nine separate proofs and an almost complete set of his prints.’
    3. 2.3 A 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.’
    • ‘Before aging, bourbon's proof must be lowered to no higher than 125 proof using distilled water.’
    • ‘This hand-selected whiskey was bottled at 94 proof in elegantly sculpted decanters.’
  • 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’
    • ‘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.’
    • ‘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.’
    • ‘She explained that 12 staff joined colleagues from across the county to update their training in the use of the chemical-proof suits.’
    • ‘Inclinations towards freedom, however, are not proof against systematic countermeasures.’
    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’
    • ‘A proof print is an example taken when the work is incomplete or not ready for publication.’
    • ‘The following categories of nationalistic blessing and their proof texts indicate they do.’
    • ‘Students helped enter more than 800,000 entries, and helped with proof reading.’
    • ‘I am continuing to work on my book, proof reading and such.’
    • ‘Having been sent an early proof copy, I have already been using it for some months.’
    • ‘You know, I don't really mind people selling proof copies on e-bay.’
    • ‘I am always impressed with accurate proof reading.’
    • ‘Then the printer stepped in, rubbed ink on the raised lines and made several proof copies from the relief block.’
    • ‘Next came the bound proof copies, incorporating quite long extracts from these letters.’
    • ‘Keynes was asked to comment on the proof copy of the work.’
    • ‘No, I don't mind people buying proof copies, but I'd advise against buying them to collect.’
    • ‘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.’
    • ‘I read this short novel a few months ago, in a proof copy, knowing nothing about the author.’
    • ‘Then a set of proof prints is sent to the artist to review.’


  • 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’
    • ‘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.’
    • ‘When their concepts were finalized, students made a working model by proofing their work in black and white on the artroom's laser printer.’
    set in print, send to press, run off, preprint, reprint, pull, proof, copy, reproduce
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    1. 2.1 Proofread (a text):
      ‘William proofed much of her work’
      • ‘Vitally, this interval permitted the whole paper to be proofed before printing.’
      • ‘Her mother was already at the table proofing the documents she would need that day for her board meeting.’
      • ‘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.’
      • ‘I don't even know what the job is, but I'll proof milk cartons at this point.’
      • ‘He was asking me to proof something I'd already proofed, saying they'd made more changes.’
      • ‘Together we evolved a monthly theme, subbed, rewrote and proofed the magazine.’
      • ‘She also has had all contact with authors, edited and tagged the journal pages, and proofed them.’
      • ‘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. 3.1 Knead (dough) until light and smooth.
    2. 3.2[no object] (of dough) prove:
      ‘shape into a baguette and let proof for a few minutes’
      • ‘Brush lightly with egg wash, cover with a damp cloth, and set aside to proof until double in volume, about 30 minutes.’
      • ‘If you're proofing at higher temperatures, your dough will rise faster, so you'll need to keep an eye on it.’


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.