proof

B2 · Upper Intermediate Countable noun Mathematics Academic

n. a series of logical steps used to show that a math rule is true.

n. 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.”

C1 · Advanced Countable noun Technical

n. a trial copy of a document or photo used to check for mistakes before the final version is printed.

n. 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.”

C2 · Proficiency Uncountable noun American English · Technical

n. a measurement of how much alcohol is in a drink.

n. 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.”

B2 · Upper Intermediate

adj. able to resist or protect against something, like water or fire.

adj. 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.”

C1 · Advanced Technical

v. to treat something so that it is protected from things like water.

v. 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.”

C1 · Advanced Cooking Technical

v. to let bread dough rise before baking it.

v. 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.”

B2 · Upper Intermediate Informal

v. to read through a text to find and fix mistakes.

v. 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.”