verb (used with object)

Origin of proof

1175–1225; Middle English prove, prooff, prof, proufe, alteration (by association with the vowel of prove) of preove, proeve, prieve, pref < Middle French preve, proeve, prueve < Late Latin proba a test, akin to Latin probāre to test and find good; cf. pree
Related formsre-proof, verb (used with object)un·proofed, adjective

Synonyms for proof

Synonym study

1. See evidence.


a combining form meaning “resistant, impervious to” that specified by the initial element: burglarproof; childproof; waterproof. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for proof

Contemporary Examples of proof

Historical Examples of proof

British Dictionary definitions for proof



any evidence that establishes or helps to establish the truth, validity, quality, etc, of something
law the whole body of evidence upon which the verdict of a court is based
maths logic a sequence of steps or statements that establishes the truth of a propositionSee also direct (def. 17), induction (def. 4), induction (def. 8)
the act of testing the truth of something (esp in the phrase put to the proof)
Scots law trial before a judge without a jury
printing a trial impression made from composed type, or a print-out (from a laser printer, etc) for the correction of errors
(in engraving, etc) a print made by an artist or under his supervision for his own satisfaction before he hands the plate over to a professional printer
photog a trial print from a negative
  1. the alcoholic strength of proof spirit
  2. the strength of a beverage or other alcoholic liquor as measured on a scale in which the strength of proof spirit is 100 degrees


(usually postpositive foll by against) able to resist; impervious (to)the roof is proof against rain
having the alcoholic strength of proof spirit
of proved strength or impenetrabilityproof armour


(tr) to take a proof from (type matter, a plate, etc)
to proofread (text) or inspect (a print, etc), as for approval
to render (something) proof, esp to waterproof

Word Origin for proof

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


adjective, combining form

secure against (damage by); (make) impervious towaterproof; mothproof; childproof

Word Origin for -proof

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

Word Origin and History for proof

early 13c., preove "evidence to establish the fact of (something)," from Anglo-French preove, Old French prueve "proof, test, experience" (13c., Modern French preuve), from Late Latin proba "a proof," a back-formation from Latin probare "to prove" (see prove). "The devocalization of v to f ensued upon the loss of final e; cf. the relation of v and f in believe, belief, relieve, relief, behove, behoof, etc. [OED].

Meaning "act of proving" is early 14c. Meaning "act of testing or making trial of anything" is from late 14c., from influence of prove. Meaning "standard of strength of distilled liquor" is from 1705. In photography from 1855. Typographical sense of "trial impression to test type" is from c.1600. Numismatic sense of "coin struck to test a die" is from 1762; now mostly in reference to coins struck from highly polished dies, mainly for collectors.

Adjectival sense (proof against) is recorded from 1590s, from the noun in expressions such as proof of (mid-15c.), hence extended senses involving "tested power" in compounds such as fireproof (1630s), waterproof (1725), foolproof (1902), etc. Shakespeare has shame-proof.


1834, "to test," from proof (n.). From 1950 as short for proofread (v.). Related: Proofed; proofing.

Online Etymology Dictionary, © 2010 Douglas Harper

Science definitions for proof



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.