proof

noun

\ ˈprüf

Definition of proof

(Entry 1 of 3)

1a : 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

6a 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

8a : 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

adjective

Definition of proof (Entry 2 of 3)

1 : able to resist or repel boots that were … proof against cold and wet— Robertson 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

verb

proofed; proofing; proofs

Definition of proof (Entry 3 of 3)

transitive verb

1a : to make or take a proof or test of

b : proofread

2 : to give a resistant quality to

3 : to activate (yeast) by mixing with water and sometimes sugar or milk

Other Words from proof Synonyms & Antonyms More Example Sentences Learn More about proof

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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

These are administrative permits that are issued when a company fills out the paperwork, provides proof of insurance, and pays the fees. — Emily Deruy, The Mercury News, "San Jose issues first scooter permit to Lyft," 7 June 2019 Winner must provide proof of age, identity, and residency. — Denisa Protani, baltimoresun.com, "Enter for a chance to win tickets for two to comedian Joe Rogan June 29th at Royal Farms Arena.," 6 June 2019 Applicants are required to provide proof of identity and legal U.S. residency to obtain the new ID. — Washington Post, "The state has given all license holders with June deadlines until July 3 to ensure their licenses are Real ID compliant," 6 June 2019 More importantly, the announcement shows an industry that’s working hard to attract younger generations, and provides proof that for millennial and Gen X buyers, camper vans are the future. — Megan Barber, Curbed, "Buying a camper van just got easier with new website," 5 June 2019 French luxury-goods company LVMH Moët Hennessy Louis Vuitton SE is using Quorum to provide proof of authenticity of its luxury goods, according to a person familiar with the matter. — Sara Castellanos, WSJ, "JPMorgan, Microsoft Team Up on Blockchain," 2 May 2019 But the salaries of its biggest stars just provide further proof. — Alexis Jones, Harper's BAZAAR, "Game of Thrones Stars Could Be Making Millions Per Episode in the Final Season," 2 Apr. 2019 Some officials have argued that it has been used as a recruiting ground for al-Shabab and a base for launching attacks inside Kenya, but the officials have not provided conclusive proof. — Tom Odula, The Seattle Times, "UN document shows Kenya seeking to close Somali refugee camp," 29 Mar. 2019 Now Florida voters have until 5 pm Saturday to fix their ballots by providing proof of identity and correcting any signature problems. — Stavros Agorakis, Vox, "Florida judge sides with Democrats, giving thousands a second chance to fix their ballots," 15 Nov. 2018

Recent Examples on the Web: Adjective

Such a measure would face the same challenge reaching a veto-proof majority. — Mark Niquette, Fortune, "Trump's Mexico Tariffs Are Coming: Why It's So Hard to Stop Them," 7 June 2019 After the federal court issued an order halting the special election, the existing map was kept in place, which allowed Republicans to maintain a veto-proof majority in the state legislature for another year. — NBC News, "Dead GOP operative's files reveal North Carolina gerrymandering strategy, watchdog says," 6 June 2019 But that kind of rebuke would need a veto-proof majority in a GOP-run chamber that's been reluctant to tangle with the president. — Tom Benning, Dallas News, "Top Texas Republicans push back on Trump's Mexico tariffs, but how far will they go?," 5 June 2019 This time, Republicans warn the numbers could be higher against the president — possibly a veto-proof majority in the Senate. — Darlene Superville, The Denver Post, "GOP lawmakers warn White House they’ll try to block Trump’s Mexico tariffs," 4 June 2019 This time, Republicans warn the numbers could be higher against the president — possibly a veto-proof majority in the Senate. — chicagotribune.com, "GOP senators warn Trump over Mexico tariffs. He says they'd be 'foolish' to try to stop him.," 4 June 2019 This time, Republicans warn the numbers could be higher against the president — possibly a veto-proof majority in the Senate. — Lisa Mascaro, Time, "GOP Splits With President Trump as Senators Loudly Oppose Mexico Tariff Threat," 4 June 2019 Now, as frustration on Capitol Hill grows over Trump's latest tariff threat, a second vote could potentially command a veto-proof majority to nullify the national emergency, which in turn could undercut the border-wall effort and the new tariffs. — Anchorage Daily News, "Republican lawmakers discuss vote to block new Trump tariffs on Mexico," 4 June 2019 Just one look at the attendees is proof enough of the Metrograph’s appeal; with a bevy of press-averse directors, actors, musicians, and artists in attendance—all happily trudged through the evening's pouring rain weather to get there. — Keaton Bell, Vogue, "The Coolest New Yorkers Came Out to Celebrate the Metrograph Theater's Third Birthday," 25 Mar. 2019

Recent Examples on the Web: Verb

To critics, all this adds up to proof that Ms. Hasina seeks to dominate a nation of 165 million people. — Sadanand Dhume, WSJ, "Bangladesh’s Bad Election Choice," 28 Dec. 2018 As your baby becomes a toddler, baby-proofing the house becomes more important than ever. — Marisa Lascala, Good Housekeeping, "This Is the Age Your Kids Should Start Swimming Lessons," 3 Apr. 2019 Filtered and minimally sweetened for balance, Craneberry is proofed down to bottle strength at 30 percent ABV, highly sippable on its own or extremely mixable in cocktails. — Francine Maroukian, Popular Mechanics, "The Most Unheralded Berry Is Coming To Your Liquor Cabinet," 28 Dec. 2018 Many models suggested that, without climate-proofing, the wharf would be underwater within a few decades. — Daniela Hernandez, WSJ, "Climate’s Big Unknown: What’s Happening Beneath Antarctica’s Ice?," 29 Dec. 2018 From stocking up on important items to hurricane-proofing homes, residents in the path of the hurricane have been getting ready for days. — Jennifer Earl, Fox News, "Hurricane Florence emergency contacts to note as 'extremely dangerous' storm hits East Coast," 12 Sep. 2018 Lawrence shaded herself from the sun with a fresh alternative to the usual paparazzi-proofing baseball cap: a leather version. — Edward Barsamian, Vogue, "Jennifer Lawrence Turns the T-Shirt-and-Jeans Pairing Into an Art Form," 24 July 2018 And, as the weather gets colder, there is so much more to cover: how to winter-proof your car, how to drive cautiously in ice and snow, and how to trouble-shoot cold-weather problems. — Jasmin Radoncic, Good Housekeeping, "How to Use Jumper Cables and Jump Start a Car the Right Way," 5 Dec. 2018 This means that there isn't proof positive these structures are there. — John Wenz, Popular Mechanics, "Menacing Ice Spikes on Europa Could Endanger Future Landers," 8 Oct. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'proof.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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More Definitions for proof

proof

noun

English Language Learners Definition of proof

(Entry 1 of 2)

: something which shows that something else is true or correct

: an act or process of showing that something is true

mathematics : a test which shows that a calculation is correct

proof

adjective

English Language Learners Definition of proof (Entry 2 of 2)

formal : designed or made to prevent or protect against something harmful

See the full definition for proof in the English Language Learners Dictionary

proof

noun

\ ˈprüf

Kids Definition of proof

(Entry 1 of 2)

1 : evidence of truth or correctness “… Is there any clear proof … or is it mere hearsay?”— Robert Lawson, Rabbit Hill

2 : a printing (as from type) prepared for study and correction

3 : a test print made from a photographic negative

4 : test entry 1 sense 2 Let's put her theory to the proof.

proof

adjective

Kids Definition of proof (Entry 2 of 2)

: able to keep out something that could be harmful The seal on the bottle is proof against tampering.

Hint: The adjective proof is usually used in compounds. waterproof

proof

noun

Legal Definition of proof

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 : probate sense 1a