[ proof ]
/ pruf /
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See synonyms for: proof / proofer / proofest on Thesaurus.com



verb (used with object)



In effect, this quiz will prove whether or not you have the skills to know the difference between “affect” and “effect.”
Question 1 of 7
The rainy weather could not ________ my elated spirits on my graduation day.

Origin of proof

First recorded in 1175–1225; Middle English prove, prooff, prof, proufe, alteration (by association with the vowel of prove) of preove, proeve, prieve, pref, from Middle French preve, proeve, prueve, from Late Latin proba “a test,” akin to Latin probāre “to test and find good”; cf. pree
1. See evidence.
Proof entered English in the 12th century as Middle English prove, prooff, prof, proufe, with the meaning “evidence sufficient to establish a thing as true.” It finds its roots in Late Latin proba, meaning "a test." An example of proof meaning “test” is in the English proverb “All the proof of a pudding is in the eating,” first recorded in English in 1605. The proverb is popularly but wrongly attributed to Miguel Cervantes. In the second part of Cervantes’ Don Quixote (published in 1615), Cervantes wrote “Por la muestra se conoce el paño,” literally, “From the sample you know the cloth,” which was translated into English as “The proof of a pudding is in the eating” by Peter Anthony Motteux, a French-born English playwright and translator, in his English translation (third edition 1712). We know this today as the saying “The proof is in the pudding.”
re-proof, verb (used with object)un·proofed, adjective

Definition for proof (2 of 2)


a combining form meaning “resistant, impervious to” that specified by the initial element: burglarproof; childproof; waterproof.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for proof (1 of 2)

/ (pruːf) /




C13: from Old French preuve a test, from Late Latin proba, from Latin probāre to test

British Dictionary definitions for proof (2 of 2)


adjective, combining form

secure against (damage by); (make) impervious towaterproof; mothproof; childproof
from proof (adj)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for proof

[ prōōf ]

A demonstration of the truth of a mathematical or logical statement, based on axioms and theorems derived from those axioms.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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