DictionaryAI

proof

SayPROOF/pɹuf/UK/pɹuːf/

Pluralproofs (some meanings)

Verbproofs, proofing, proofed

17 meanings of proof

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  1. 1
    evidencenoununcountable
    Evidence, an argument or a document that shows, or helps to show, that something is true.

    The prosecution offered fingerprints as proof of the defendant's presence at the scene.

    Despite years of searching, no one has found proof that the treasure exists.

    UsageUsually proof of something or proof that it is true; no proof, some proof. The verb is prove.

    Similartestament

    Oppositedisproof, refutation

    Note

    Where the trial sense names the testing, this one names what the testing yields: the evidence that settles belief. It is usually uncountable here (some proof, no proof, proof of), though countable uses also occur, and no proof of is a natural frame, as in the line of Swedenborg's that Emerson quotes in "The Over-Soul": "It is no proof of a man's understanding…"

  2. 2
    mathnouncountable
    A sequence of statements, each an axiom, an assumption, a previously demonstrated result, or a logical consequence of earlier statements, ending with the statement to be established.

    Like a chain of dominoes: each statement knocks the next into place until the last one falls exactly where you said it would.

    Euclid's proof of the infinitude of primes is admired for its elegance.

    She spent the weekend checking every step of the proof for errors.

    UsageUsually a proof of a result or a proof that something holds; mathematicians give, write or check a proof.

    Similardemonstration, derivation

    Oppositedisproof

    Note

    In mathematics and logic, proof is a matter of form rather than persuasion. Every step has to be licensed, and nothing counts merely because it convinces. That is what separates it from proof as convincing evidence, which only needs to settle belief.

  3. 3
    safe againstadjective
    Firm or successful in resisting; able to withstand a particular force or influence.

    The fortress walls were proof against cannon fire of the period.

    No politician is entirely proof against flattery.

    UsageUsually proof against something: proof against fire. As a word ending it follows the thing resisted: waterproof, bulletproof.

    Similarresistant, impervious, immune, invulnerable

    Oppositevulnerable, susceptible

    Note

    The adjective shares its idea of tested, unyielding strength with armor of proof, and it usually follows a verb such as be. Milton's Paradise Regain'd (1671) finds his hero 'Proof against all temptation as a rock / Of Adamant'. Edmund Burke's Reflections on the Revolution in France (1790) sets it before a noun: a stout proof article of faith.

  4. 4
    test printnouncountable
    A trial impression of typeset or printed material, taken so errors can be examined and corrected before final printing.

    The designer sent the client a proof of the wedding invitation for approval.

    Compositors once pulled proofs by hand to check each freshly set page.

    UsageOften plural for a whole book: the proofs. People check or correct a proof of a page.

    Similardraft, mock-up

    Note

    The printer's version of a trial: an impression pulled before the real run so mistakes can be caught. Its fuller name is proof sheet. Checking it is proofreading, which colloquially shrinks to the verb proof. Andrea Levy's The Long Song (2010) captures the work in men who 'scour the printed proof for error, blunder, and misspelling.'

    Checked 6 Nov 2026 · 2 facts

    • Andrea Levy wrote The Long Song, first published in 2010. andrealevy.co.uk
    • The quoted words occur in The Long Song and describe men checking printed proofs. en.wiktionary.org
  5. 5
    nouncountable
    The testing of something to find out whether it is true, accurate, strong, or reliable: the trial itself, not the evidence or argument it produces, as in put to the proof.

    The long, hard winter put their young friendship to the proof.

    The proof of the pudding is in the eating, as the old saying goes.

    UsageMostly in set phrases: put something to the proof; the proof of the pudding is in the eating.

    Note

    Here proof is a trial, not a result. When Spenser's fox puts every art 'in proof', he puts it to the test. Thomas Thomson in 1831 describes spirits tried this way: poured on gunpowder and set alight to see whether the powder would still fire.

  6. 6
    verbtransitive
    To treat something so as to make it resistant, especially to water.

    The manufacturer proofs each jacket against rain before shipping.

    Climbers proof their canvas packs with wax to survive wet conditions.

    UsageOften proof something against water or rain.

    Similarwaterproof, seal, treat, weatherproof

  7. 7
    check writingverbcolloquialtransitive or intransitive
    To read written or printed material in order to find and correct errors; to proofread.

    An intern proofs every press release before it goes out.

    He used to proof for a legal publisher, catching errors others missed.

    UsageA short form of proofread, which is the usual word in careful writing.

    Similarproofread, check, edit, copyedit

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Origin

The ultimate source is Latin "probo" ("to prove"), which gave Late Latin "proba" ("a proof"); that passed through Old French "prove" into Middle English "proof." "Probe" is its doublet.