proof

1 of 3

noun

1
a
: the cogency of evidence that compels acceptance by the mind of a truth or a fact
b
: the process or an instance of establishing the validity of a statement especially by derivation from other statements in accordance with principles of reasoning
2
obsolete : experience
3
: something that induces certainty or establishes validity
4
archaic : the quality or state of having been tested or tried
especially : unyielding hardness
5
: evidence operating to determine the finding or judgment of a tribunal
6
a
plural proofs or proof : a copy (as of typeset text) made for examination or correction
b
: a test impression of an engraving, etching, or lithograph
c
: a coin that is struck from a highly polished die on a polished planchet, is not intended for circulation, and sometimes differs in metallic content from coins of identical design struck for circulation
d
: a test photographic print made from a negative
7
: a test applied to articles or substances to determine whether they are of standard or satisfactory quality
8
a
: the minimum alcoholic strength of proof spirit
b
: strength with reference to the standard for proof spirit
specifically : alcoholic strength indicated by a number that is twice the percent by volume of alcohol present
whiskey of 90 proof is 45 percent alcohol

proof

2 of 3

adjective

1
: able to resist or repel
boots that were … proof against cold and wetRobertson Davies
often used in combination
windproof
2
: used in proving or testing or as a standard of comparison
3
: of standard strength or quality or alcoholic content

proof

3 of 3

verb

proofed; proofing; proofs

transitive verb

1
a
: to make or take a proof or test of
b
2
: to give a resistant quality to
3
: to activate (yeast) by mixing with water and sometimes sugar or milk
proofer noun

Examples of proof in a Sentence

Noun The document was proof that her story was true. He claims that he was home when the murder was committed, but he has no proof. The proof shows that the theorem is true. Verb She proofed the story carefully.
Recent Examples on the Web
Noun
The Biden clan has shown up in force to a trial on charges that are almost never filed as a standalone case — proof to many that he’s being made an example because his father is president. Matt Hamilton, Los Angeles Times, 10 June 2024 Great smartphones don't have to cost a fortune and the OnePlus Nord N30 is proof of that. Gabriela Vatu, PCMAG, 10 June 2024
Adjective
Fashion Week was definitely proof that this trend has made its way from athletic attire into street style, and one pair that combines both fashion and comfort is this on-sale, super-supportive find Rocket Dog. Lane Nieset, Travel + Leisure, 23 May 2024 Studies show no link between vaccines, autism The post attempts to blame the autism increase on legislation that reduced liability for vaccine manufacturers, but that line of reasoning falls short since an array of studies have found no proof vaccines have any link to autism. Chris Mueller, USA TODAY, 17 May 2024
Verb
Lamination includes folding butter (preferably French) into dough again and again, creating the many billowy-on-the-inside and flaky-on-the-outside layers that implode when bitten into, before being shaped, proofed, and baked. Amy Thomas, Vogue, 11 June 2024 Feng says this is a testament to how Taiwan has earthquake proofed itself in the last two decades. Mansee Khurana, NPR, 3 Apr. 2024 See all Example Sentences for proof 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'proof.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Noun

Middle English prof, prove, alteration of preve, from Anglo-French preove, from Late Latin proba, from Latin probare to prove — more at prove

First Known Use

Noun

13th century, in the meaning defined at sense 1a

Adjective

1583, in the meaning defined at sense 1

Verb

circa 1699, in the meaning defined at sense 1a

Time Traveler
The first known use of proof was in the 13th century

Dictionary Entries Near proof

Cite this Entry

“Proof.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/proof. Accessed 22 Jun. 2024.

Kids Definition

proof

1 of 3 noun
1
a
: evidence of truth or correctness
gave proof of her statement
b
: an act or process of showing or finding out that something is true especially by reasoning or by experiment
a proof that the theorem is true
put a theory to the proof
2
a
: a copy (as of something set in type) taken for study and correction
b
: a test print made from a photographic negative

proof

2 of 3 adjective
: designed or made to prevent or keep out something that could be harmful
this lock is proof against tampering
often used in compounds
waterproof

proof

3 of 3 verb
: to activate (yeast) by mixing with water

Legal Definition

proof

noun
1
: the effect of evidence sufficient to persuade a reasonable person that a particular fact exists see also evidence
2
: the establishment or persuasion by evidence that a particular fact exists see also burden of proof
3
: something (as evidence) that proves or tends to prove the existence of a particular fact see also clear and convincing, preponderance of the evidence, reasonable doubt, standard of proof compare allegation, argument
4
Etymology

Noun

alteration of Middle English preove, from Old French preuve, from Late Latin proba, from Latin probare to prove

More from Merriam-Webster on proof

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