proof

\ 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 combinationwindproof

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 That doesn’t mean the pet industry is recession-proof in the current upheaval, but pet-supply seller Chewy has seen sales surge – an uptick also driven by a more general migration of consumers online during the pandemic. — Laurent Belsie, The Christian Science Monitor, "‘We’ve sold thousands of bikes’: The businesses surging at a tough time," 5 June 2020 The most deer-proof of the list of plants described in this article is thryallis. — Calvin Finch, ExpressNews.com, "Calvin Finch: Full-color summer shrubs for your San Antonio garden," 4 June 2020 Buy now: Bamboo bath mat, $30, amazon.com For the Italian food addict whose tomatoes are flourishing in quarantine Any gardener will be grateful for a new set of machine washable, puncture-proof gloves. — Alex Erdekian, Condé Nast Traveler, "25 Gifts Under $100 For People Who Can't Wait to Travel Again," 28 May 2020 Another is that the late Mrs. Soprano was so manipulative, embittered, narcissistic, and homicidal as to render her entirely eulogy-proof. — Kathryn Schulz, The New Yorker, "You’ve Got Chain E-Mail," 15 May 2020 It’s made of durable, water-repellent, fade-proof fabric that’s striped on one side and reverses to a solid color on the other. — Kathy Passero, al, "Ready for Memorial Day? From pools to picnics, 10 great items to help you celebrate the unofficial start of summer," 15 May 2020 Besides its ultra-sanitized work environment, ASML has the benefit of making machines that are considered almost recession-proof, given its commanding lead in an industry on the cusp of another technological leap: high-speed 5G networks. — Natalia Drozdiak, Bloomberg.com, "Shielded from Pandemic, Work Continues in World’s Cleanest Room," 13 May 2020 The National Academy of Sciences study shows the result of this proof-of-principle demonstration. — John Fialka, Scientific American, "Ultrasensitive Fuel Gauges Could Improve Electric Vehicle Batteries," 12 May 2020 Chairs that are foldable, lightweight, durable, weather-proof, and without armrests are best, says Green. — : Bob Mcnally, Field & Stream, "The Complete Guide To Spider-Rigging For Crappies," 7 May 2020 Recent Examples on the Web: Adjective Yes, this bag is made by a company predominantly known for their bullet-proof coolers. — Outdoor Life, "High-performance bags for any kind of travel," 4 May 2020 Some of my colleagues who own bullet proof vests are wearing them. — Sarah Midkiff, refinery29.com, "Trump Called Michigan Protesters “Good People”," 3 May 2020 Through nerve, cunning, a skillet filled with boiling oil and the gruesome misuse of an underling — deployed as a bullet-proof vest — Lalo survived an armed home invasion against very steep odds. — David Segal, New York Times, "‘Better Call Saul’ Season 5 Finale Recap: Close Calls," 20 Apr. 2020 Inside was an officer, a large man wearing a bullet-proof vest. — Sam Roe, Milwaukee Journal Sentinel, "Sam Roe: A child's ball rolls over. Should I throw it back? With coronavirus, right and wrong are turned upside down.," 31 Mar. 2020 Last season was proof positive that this team needs a better backup plan behind Ben Roethlisberger, now 38 and coming off elbow surgery. — Nate Davis, USA TODAY, "NFL second-round mock draft 2020: Where do Jalen Hurts, best available players land?," 24 Apr. 2020 Once the sugar is starting to melt, give it a stir with a heat-proof spatula or wooden spoon. — Katlyn Moncada, Better Homes & Gardens, "I Tried the 3-Ingredient Crème Brûlée, and Yes, It's as Easy (and Delicious) as It Sounds," 21 Apr. 2020 The outer splash-proof pocket and inner cell-phone-and-keys pouch are a nice touch. — Outdoor Life, "Four weather-proof backcountry dry bags," 15 Apr. 2020 Don’t be skeptical given the number after the dollar symbol, reviewers raved about this vacuum sealer, citing its ease of use and praising its secure and leak proof seal during sous vide cooking. — Gabrielle Hondorp, Popular Mechanics, "The 7 Best Food Vacuum Sealers To Keep Your Meals Fresh," 8 Apr. 2020 Recent Examples on the Web: Verb Too cold of conditions might delay proofing or rising, creating a super-dense loaf. — Karla Walsh, Better Homes & Gardens, "7 Bread Machine Mistakes You’ll Never Make Again," 29 May 2020 Experts also say having antibodies is not necessarily proof someone is immune to the virus. — USA TODAY, "Fast food jam, virtual Derby, mask seizures: News from around our 50 states," 24 Apr. 2020 Dough that needs to proof or chill for a few hours? — Amanda Mull, The Atlantic, "The Pandemic Has Reminded Americans They Are Capable of Baking," 12 May 2020 Newer multifamily developments may future-proof their garages to accommodate EV adoption, but older buildings face prohibitively expensive installation costs that leave residents reliant on workplace or public chargers. — Nathaniel Horadam, Ars Technica, "Are electric vehicles doomed? We don’t think so, despite poor sales," 27 Apr. 2020 The agility of the urban form across Africa and the diverse range of actors involved in urban development represents an opportunity to take a global lead on innovative approaches to future-proofing health in rapidly growing cities. — Tolu Oni, Quartz Africa, "This is the best time to plan for urban Africa’s next health emergency," 16 Apr. 2020 The connection is purely an association rather than proof the drugs cause autism. — Nicholette Zeliadt, New York Times, "What Causes Autism?," 20 Apr. 2020 Your dogs and cats can also bring the pests inside, so check them and tick-proof your yard. — Jen Christensen, CNN, "What is Lyme disease? Things you should know," 8 Jan. 2020 Forward-thinking companies can also future-proof their business from the inside, like the hundreds of companies that have already committed to reducing their carbon emissions and shifting to 100% renewable energy. — CNN, "Disasters like the Australia fires happen when businesses ignore the climate," 21 Jan. 2020

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.