View synonyms for proof



[ proof ]


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

    Synonyms: support, corroboration, demonstration, confirmation

  2. anything serving as such evidence:

    What proof do you have?

  3. the act of testing or making trial of anything; test; trial:

    to put a thing to the proof.

    Synonyms: assay, examination

  4. the establishment of the truth of anything; demonstration.
  5. Law. (in judicial proceedings) evidence having probative weight.
  6. the effect of evidence in convincing the mind.
  7. an arithmetical operation serving to check the correctness of a calculation.
  8. Mathematics, Logic. a sequence of steps, statements, or demonstrations that leads to a valid conclusion.
  9. a test to determine the quality, durability, etc., of materials used in manufacture.
  10. Distilling.
    1. the arbitrary standard strength, as of an alcoholic liquor.
    2. strength with reference to this standard: “100 proof ” signifies a proof spirit, usually 50% alcohol.
  11. Photography. a trial print from a negative.
  12. Printing.
    1. a trial impression, as of composed type, taken to correct errors and make alterations.
    2. one of a number of early and superior impressions taken before the printing of the ordinary issue:

      to pull a proof.

  13. (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.
  14. 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.
  15. the state of having been tested and approved.
  16. proved strength, as of armor.
  17. 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.

    Synonyms: steadfast, firm

  2. impenetrable, impervious, or invulnerable:

    proof against outside temperature changes.

  3. used for testing or proving; serving as proof.
  4. of standard strength, as an alcoholic liquor.
  5. of tested or proven strength or quality:

    proof armor.

  6. 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 ).
  3. to proofread.
  4. 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.

  5. Cooking.
    1. to test the effectiveness of (yeast), as by combining with warm water so that a bubbling action occurs.
    2. to cause (especially bread dough) to rise due to the addition of baker's yeast or other leavening.


  1. a combining form meaning “resistant, impervious to” that specified by the initial element:

    burglarproof; childproof; waterproof.




  1. secure against (damage by); (make) impervious to






/ 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
  3. maths logic a sequence of steps or statements that establishes the truth of a proposition See also direct induction induction
  4. the act of testing the truth of something (esp in the phrase put to the proof )
  5. Scots law trial before a judge without a jury
  6. printing a trial impression made from composed type, or a print-out (from a laser printer, etc) for the correction of errors
  7. (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
  8. photog a trial print from a negative
    1. the alcoholic strength of proof spirit
    2. 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 postpositivefoll byagainst able to resist; impervious (to)

    the roof is proof against rain

  2. having the alcoholic strength of proof spirit
  3. 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
  3. to render (something) proof, esp to waterproof


/ pro̅o̅f /

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

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Other Words From

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

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Word History and Origins

Origin of proof1

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”; pree

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Word History and Origins

Origin of proof1

from proof (adj)

Origin of proof2

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

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Synonym Study

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Example Sentences

Park employees helped John quit tobacco by way of a butts-proof glass enclosure, a drastic change in diet, and regular exercise.

Although often this is considered proof positive of guilt at trial, it is not an uncommon occurrence in false confessions.

And if you want proof of what the country is really all about, just walk through the National September 11 Memorial Museum.

They're also proof that no matter how fancy you are, you can't escape the urge to watch two girls make out.

Without proof of this kind, the story of the lost legions is just a legend.

Here convincing proof was given of Mme. Mesdag's accuracy, originality of interpretation, and her skill in the use of color.

Proof was given to him, of Elizabeth having admitted Ripperda to private political discussions in the Altheim apartments.

Wasn't the dead man stretched in the shadow convincing proof of their capacity for pure devilishness?

For my part, I scarcely know what to say; inasmuch as I do not care either to affirm or deny a thing of which I have no proof.

If I am proof against my own heart, in so dear a cause, shall I not be proof against the poor allurements of vanity and sense?


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Words That Use -proof

What does -proof mean?

The combining formproof is used like a suffix meaning “resistant, impervious to.” Impervious means “impenetrable.” It is occasionally used in a variety of everyday and technical terms.

The form –proof ultimately comes from Latin proba, meaning “test.”

Examples of -proof

One example of a term that uses the form –proof is soundproof, “impervious to sound.”

The first part of the word, sound, means “sound” or “noise.” As we have seen, –proof means “resistant.” Soundproof literally means “resistant to sound.”

What are some words that use the combining form –proof?

What are some other forms that –proof may be commonly confused with?

Break it down!

Given the meaning of –proof, what does childproof mean?