proof

¹

[proof]

noun

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.

adjective

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.

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.

-proof

²

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

   burglarproof; childproof; waterproof.

-proof

¹

adjective

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

   waterproof

   mothproof

   childproof

proof

²

/ pruːf /

noun

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

9. 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

adjective

1. 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

verb

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

proof

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

Other Word Forms

• re-proof verb (used with object)
• unproofed adjective

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

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

Synonym Study

See evidence.

Example Sentences

It’s been a brutal year for so many in L.A., and the chance to finally throw back as much beer as the Rose Bowl will serve you and scream along to “Acquiesce” and “Morning Glory” is proof anyone — even the Gallagher brothers — can find a way to reconcile and recover.

From Los Angeles Times

Death threats and backlash from those in power were regular responses to Oliphant’s work, reactions he welcomed as proof of a job well done.

From Salon

The fact that these goofs hold managerial positions is proof that the structures designed to aid the vulnerable aren’t working as they should, and on purpose.

From Salon

If you need proof that sometimes one picture really is worth 1,000 words, check out this week’s photo of Putin, Chinese President Xi Jinping, and Indian President Narendra Modi smiling and holding hands at a summit in China, joined later by an equally jolly Kim Jong-un, the dictator of North Korea.

From Slate

For viewers at home, it was proof that the skills she demonstrated weren’t locked behind a restaurant door; they were achievable in your own kitchen.

From Salon

Related Words

• argument 
• clue 
• confirmation 
• criterion 
• data 
• demonstration 
• information 
• picture 
• reason 
• testament 
• testimony 
• validation 
• verification 

When To Use

What does -proof mean?

The combining form -proof 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.”