# proof /ˈpɹuf/ (US) · /pɹˈuːf/ (UK) Source: https://englishreference.com/word/proof Updated: 2026-06-19 ## Senses ### 1. evidence of truth noun · CEFR B1 information or evidence that shows something is definitely true. For teachers: conclusive evidence or a body of facts that establishes the validity of a statement or the truth of a fact. - The police found a video that provided clear proof of his innocence. - The prosecution struggled to provide definitive proof of the defendant's involvement, as most of the forensic evidence had been contaminated at the scene. ### 2. mathematical logic noun · CEFR B2 · Academic a series of logical steps used to show that a math rule is true. For teachers: a formal sequence of logical steps, starting from axioms, that demonstrates the truth of a mathematical or logical proposition. - The teacher asked the students to write a proof for the geometry problem. - The mathematician spent years developing a rigorous proof for the theorem, which had remained unverified for over a century. ### 3. printing/photography noun · CEFR C1 · Technical a trial copy of a document or photo used to check for mistakes before the final version is printed. For teachers: a preliminary version of a printed piece, such as a page or photograph, produced for review and correction before the final production run. - The author spent the afternoon checking the page proofs for spelling errors. - Before the magazine went to press, the editor insisted on reviewing the colour proofs to ensure the photography was reproduced accurately. ### 4. alcohol content noun · CEFR C2 · American English · Technical a measurement of how much alcohol is in a drink. For teachers: a measure of the ethanol content in an alcoholic beverage, traditionally defined in the US as twice the percentage of alcohol by volume. - This whiskey is 80 proof, which means it contains 40 percent alcohol. - The distillery produced a high-proof spirit intended specifically for blending, rather than for direct consumption. ### 5. resistant to adjective · CEFR B2 able to resist or protect against something, like water or fire. For teachers: impervious or resistant to a specific damaging agent; often used as a suffix in compound words. - No system is completely proof against hackers if they are determined enough. - The bunker was designed to be proof against even the most powerful conventional explosives available at the time. Usage: Usually follows the noun it modifies or functions as a suffix, as in 'waterproof' or 'bulletproof'. ### 6. to make resistant verb · CEFR C1 · Technical to treat something so that it is protected from things like water. For teachers: to treat a surface or material with a substance that makes it resistant to a specific external force or element. - You should proof your boots with a special spray before going hiking in the rain. - The contractor recommended that we proof the exterior masonry to prevent moisture from seeping into the structural timber during the winter months. ### 7. baking dough verb · CEFR C1 · Technical to let bread dough rise before baking it. For teachers: to allow yeast-leavened dough to rise, typically after shaping, to achieve the desired volume and texture before baking. - Let the rolls proof in a warm place for about an hour until they double in size. - If you fail to proof the dough sufficiently, the resulting loaf will be dense and lack the airy crumb characteristic of a well-made sourdough. ### 8. to proofread verb · CEFR B2 · Informal to read through a text to find and fix mistakes. For teachers: to read and mark corrections in a manuscript or printed proof. - Could you proof this email for me before I send it to the boss? - The intern was tasked to proof the final draft of the annual report, ensuring that all financial figures aligned with the provided spreadsheets. ## Examples - Do you have any proof of your identity? - The scientist presented clear proof that the new medicine works better than the old one. - While the initial data suggested a correlation, the researchers required further longitudinal studies to provide definitive proof of a causal relationship between the two variables. --- From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.