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

Keep scrolling for more

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

Heat oil in a large oven-proof skillet on medium-high. — Woman's Day Kitchen, Woman's Day, "Lemon-Thyme Chicken with Spring Sauté," 7 Mar. 2019 However, proof that there is more love in this world than hate. — Henry Youtt, Billboard, "Sam Smith Pays Emotional Visit to Pulse Nightclub: 'There Is More Love in This World Than Hate'," 13 July 2018 Conclusive proof that players who have the ability and mindset to make it at Chelsea, via the loan system, will be able to go on to do just that. — SI.com, "The Winning Way: Why More Top European Clubs Should Adopt Chelsea's Much Debated Loan Policy," 12 July 2018 The latest proof: A record number are voluntarily quitting to seek better jobs. — Shobhana Chandra, chicagotribune.com, "A record number of Americans are quitting their jobs," 10 July 2018 The band tweeted proof of their fearless leader’s injury after the show. — Lydia Price, PEOPLE.com, "13 Brave Singers Who Survived Absolutely Brutal Stage Falls," 9 July 2018 The latest proof came just after midnight Friday, in the form of $34 billion in new tariffs imposed on Chinese imports. — Evan Horowitz, BostonGlobe.com, "There are no bullets or bombs, but trade wars have real casualties," 6 July 2018 This practice is proof, immigrant advocates say, that the Trump administration did a terrible job tracking where people were going when first separated. — Adam K. Raymond, Daily Intelligencer, "DNA Tests Are Being Used to Reunite Separated Migrant Families," 5 July 2018 This time, in Milan, everything came together perfectly—take the audible gasps heard in the front row when Seymour appeared as proof. — Steff Yotka, Vogue, "“Who Wouldn’t Want to Do the Versace Show?” Stephanie Seymour Reflects on Her Milan Comeback," 25 Feb. 2019

Recent Examples on the Web: Adjective

Just last week, a Chadds Ford school made headlines for the graduation gifts its eighth graders would receive: bullet-proof backpack shields. — Aubrey Nagle, Philly.com, "Schools buy war-zone trauma kits, Trump-Kim summit recap | Morning Newsletter," 12 June 2018 Here are five leak-proof travel containers that’ll keep your airplane food safe, sound, and ready to eat. — Elaheh Nozari, Bon Appetit, "5 Leak-Proof Containers for Safely Stowing Your Airplane Food," 10 May 2018 Lawmakers passed the bill to remove naloxone age barriers with veto-proof numbers. — Jon Kamp, WSJ, "Maine Lawmakers Clash With Governor Over Naloxone Access," 16 Apr. 2018 About 500 people responded, with bullet-proof glass, door locks, metal detectors and fencing among the security items mentioned repeatedly, officials said. — Leslie Postal, OrlandoSentinel.com, "School-safety measures will take time, cost a lot, districts say," 2 Apr. 2018 Dasti was traveling in a bullet-proof vehicle, but his guards were not. — Washington Post, "Bomb kills 4 troops, gunmen kill 2 police guards in Pakistan," 28 Feb. 2018 This walk-in campground has (much needed) bear-proof food storage containers, fire pits, free firewood, and a small warming shelter. — Sunset, "32 Best Free Camping Sites," 22 Jan. 2018 Use white glue, carpenter’s glue, water-proof glue, or epoxy. — Roy Berendsohn, Popular Mechanics, "Waste Not: 6 Things You Can Do With Sawdust and Wood Shavings," 20 Nov. 2018 The company announced the upcoming Echo Dot Kids Edition last week, which features a kid-proof case and a one-year subscription to Amazon FreeTime Unlimited. — Valentina Palladino, Ars Technica, "Amazon Prime members can get monthly box of kids’ books with new subscription," 1 May 2018

Recent Examples on the Web: Verb

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 Wet n Wild Photo Focus Foundation Wet n Wild tested this formula under seven different lighting conditions with top smartphone models to essentially selfie-proof their product. — Allure, "The 17 Best Drugstore Foundations for All Your Coverage Needs," 6 Sep. 2018 Theater people have the best advice on sweat-proofing makeup Who among us hasn’t pirouetted all night (literally or figuratively) and felt their foundation start to slide off? — Jamie Beckman, Allure, "Backstage Beauty Secrets From the Cast and Crew of Hamilton and Sleep No More," 13 Aug. 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.

Keep scrolling for more

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