proof

noun
\ ˈprüf How to pronounce proof (audio) \

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

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Other Words from proof

Verb

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.
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Recent Examples on the Web: Noun Guests will be required to show proof of vaccination or a recent COVID-19 infection or else take a rapid COVID-19 test before the event. Russell Blair, courant.com, "Thousands of college students in Connecticut are graduating in person this year after COVID-19 shut down campuses a year ago. Here’s a school-by-school look.," 7 May 2021 Amtrak is paying employees two hours’ worth of regular wages per shot upon proof of vaccination. New York Times, "Health Advocate or Big Brother? Companies Weigh Requiring Vaccines.," 7 May 2021 Travelers must have proof of a negative Covid test in order to travel into French Polynesia. Lilit Marcus, CNN, "Tahiti and the rest of French Polynesia has reopened to tourism," 7 May 2021 The state is offering residents the ability to show digital proof of their COVID-19 vaccinations on their cellphones. From Usa Today Network And Wire Reports, USA TODAY, "Ballpark bargain, beef passports, concerts for the vaccinated: News from around our 50 states," 7 May 2021 The moment was one part triumph of the human spirit, one part proof that beauty is in the eye of the beholder. Tim Alberta, The Atlantic, "Elvis Reenters the Building," 7 May 2021 Every possible economic outcome is considered proof that stimulus works. Brian Riedl, National Review, "Weak Jobs Report Shows Limits of ‘Stimulus’," 7 May 2021 Autoplay Yellowstone and Grand Teton national parks have resumed large group tours with safety measures intended to limit the spread of COVID-19, including wearing masks and being tested with 72 hours before the trip or showing proof of vaccination. Fox News, "Yellowstone, Grand Teton national parks to resume bus operations," 7 May 2021 Outdoor conventions, meetings and receptions can resume with up to 200 people, and up to 400 people if all attendees provide proof of vaccination or a negative coronavirus test. Aidin Vaziri, San Francisco Chronicle, "Here's the next Bay Area county set to move into the yellow tier," 6 May 2021 Recent Examples on the Web: Adjective Now that our antibodies gave us darn near bullet-proof resistance to the virus, Joanne called our friends, Roger and Janey. Arkansas Online, "Jail break," 8 May 2021 But the state Legislature has a veto-proof Democratic majority. Los Angeles Times, "Caitlyn Jenner struggles to go from OMG moment to a campaign for California governor," 7 May 2021 There isn't a full-proof way to verify that your go-to apps will work on an M1 MacBook. Patrick Moorhead, Forbes, "What’s Better, The New M1 MacBooks Or The Microsoft Surface?," 12 Apr. 2021 Matt Fugate to break down the easiest, most fool-proof way to cut your bangs, without any mistakes or regret. Tatjana Freund, Marie Claire, "How to Trim Your Own Bangs at Home Like a Pro," 29 Mar. 2021 Cuomo, a three-term governor in a state without gubernatorial term limits, has enjoyed a veto-proof Democratic legislative majority in Albany since the 2018 elections. Fox News, "Gaetz: Cuomo allegations have New York Democrats 'going after each other more than the royal family'," 13 Mar. 2021 The fact that his 2016 Super60 ranking still bothers him is proof enough. Chris Hays, orlandosentinel.com, "Former Bishop Moore star Ben DeLucas lets nothing stand in way as he eyes NFL Draft," 6 Mar. 2021 During Prohibition and the Recession, Loomis’ armored cars were made of heavy steel and had bullet-proof compartments and gun ports, according to company history. oregonlive, "Loomis armored car founder’s Portland mansion is for sale at $3.2 million," 1 Apr. 2021 The drinks would have to be packaged in tamper-proof containers with no straw holes and would have to be transported in a vehicle’s trunk, in a glove compartment or behind the last seats. From Usa Today Network And Wire Reports, USA TODAY, "Chef initiative, ice fishing trash, Tribeca plans: News from around our 50 states," 31 Mar. 2021 Recent Examples on the Web: Verb Bushnell said her team recently cheered upon releasing their 1,000th coronavirus patient, proof that the disease is still a threat. Alex Mann, baltimoresun.com, "‘The spirit of nursing’: During National Nurses Week, Maryland’s nurses reflect on COVID fight," 9 May 2021 The same day as the Carter Center photo, the president and first lady were photographed boarding Air Force One at Andrews Air Force Base in Maryland and leaving the Carters' Georgia residence, proof that the trip was real. Stephen J. Beard, USA TODAY, "Fact check: The image of the Bidens and Carters together is distorted, but very real," 7 May 2021 In this way, automakers and fleet customers alike stand to future-proof themselves with Plus and Cummins’ solution for autonomous trucks. Patrick Moorhead, Forbes, "Self-Driving Truck Company Plus Demonstrates Commitment To Sustainability With Eco-Friendly Collaborators," 27 Apr. 2021 Reporters considered the existence of a complaint to be proof the city was notified of a problem if other records confirmed the problem existed at the time of the fire. Cecilia Reyes, chicagotribune.com, "The Failures Before the Fires: How we reported this story," 24 Apr. 2021 Retailers are accelerating digitization to future-proof their business and bringing delivery automation capabilities into the core. Kashyap Deorah, Forbes, "Delivery Technology In Retail: Are We There Yet?," 16 Apr. 2021 Yet only about half of companies use scenario planning to help future-proof their strategies, according to a recent Deloitte survey of chief strategy officers. David Schatsky, Forbes, "Uncertainty And Innovation At Speed," 18 Mar. 2021 The European Union’s executive arm proposed the introduction of digital certificates that will offer proof their holders have been vaccinated, recovered from the illness or recently tested negative, and thus pose no significant health risks. Nikos Chrysoloras, Fortune, "COVID certificates for travelers seen as a lifeline for Europe’s ravaged tourism sector," 17 Mar. 2021 Why would proof of vaccine be accepted if those who have been vaccinated can still spread the virus? Catharine Hamm, Los Angeles Times, "What travelers need to know now about testing and vaccine records. Paper won’t cut it," 15 Mar. 2021

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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First Known Use of proof

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

History and Etymology for proof

Noun

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

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Time Traveler for proof

Time Traveler

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

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Statistics for proof

Last Updated

10 May 2021

Cite this Entry

“Proof.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/proof. Accessed 17 May. 2021.

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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

proof

noun
\ ˈprüf How to pronounce proof (audio) \

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

History and Etymology for proof

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

Comments on proof

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