evidence sufficient to establish a thing as true, or to produce belief in its truth.
anything serving as such evidence.
What proof do you have?
the act of testing or making trial of anything; test; trial.
to put a thing to the proof.
the establishment of the truth of anything; demonstration.
Law. (in judicial proceedings) evidence having probative weight.
the effect of evidence in convincing the mind.
an arithmetical operation serving to check the correctness of a calculation.
Mathematics, Logic. a sequence of steps, statements, or demonstrations that leads to a valid conclusion.
a test to determine the quality, durability, etc., of materials used in manufacture.
Distilling.
the arbitrary standard strength, as of an alcoholic liquor.
strength with reference to this standard: “100 proof ” signifies a proof spirit, usually 50% alcohol.
Photography. a trial print from a negative.
Printing.
a trial impression, as of composed type, taken to correct errors and make alterations.
one of a number of early and superior impressions taken before the printing of the ordinary issue.
to pull a proof.
(in printmaking) an impression taken from a plate or the like to show the quality or condition of work during the process of execution; a print pulled for examination while working on a plate, block, stone, etc.
Numismatics. one of a limited number of coins of a new issue struck from polished dies on a blank having a polished or matte surface.
the state of having been tested and approved.
proved strength, as of armor.
Scots Law. the trial of a case by a judge alone, without a jury.
able to withstand; successful in not being overcome.
proof against temptation.
impenetrable, impervious, or invulnerable.
proof against outside temperature changes.
used for testing or proving; serving as proof.
of standard strength, as an alcoholic liquor.
of tested or proven strength or quality.
proof armor.
noting pieces of pure gold and silver that the U.S. assay and mint offices use as standards.
to test; examine for flaws, errors, etc.; check against a standard or standards.
Printing. prove.
to proofread.
to treat or coat for the purpose of rendering resistant to deterioration, damage, etc. (often used in combination).
to proof a house against termites; to shrink-proof a shirt.
Cooking.
to test the effectiveness of (yeast), as by combining with warm water so that a bubbling action occurs.
to cause (especially bread dough) to rise due to the addition of baker's yeast or other leavening.
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 proposition See also direct induction induction
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
the alcoholic strength of proof spirit
the strength of a beverage or other alcoholic liquor as measured on a scale in which the strength of proof spirit is 100 degrees
able to resist; impervious (to)
the roof is proof against rain
having the alcoholic strength of proof spirit
of proved strength or impenetrability
proof 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
What does -proof mean? The combining form -proof is used like a suffix meaning “resistant, impervious to.” Impervious means "impenetrable." It is occasionally used in a variety of everyday and technical terms. The form -proof ultimately comes from Latin proba, meaning “test.”
See evidence.
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
Proof is the evidence that shows something is true or valid. When you show the logical steps that take you from your hypothesis that the world is round to the conclusion that it is, you're formulating a proof. Photographic prints that haven't been touched up are also called proofs, and that’s also what you call the first copy of a printed text, before it's checked for errors and corrected. When you check a text for errors, you're proofing. If your poker strategy is foolproof, even somebody who knows nothing about poker — a poker fool, that is — can’t get it wrong. Proof is a word you’ll see on bottles of alcohol, too: 90-proof rum means it's 45% alcohol.
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Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
He presented this as proof of concept that such a thing is possible.
From The Wall Street Journal ● Jul. 17, 2026
The researchers emphasize that the findings should not be interpreted as proof that sweeteners or the tested combinations cause harm in people.
From Science Daily ● Jul. 17, 2026
Online critics were quick to dredge up comments by a former Argentinian leader as proof of the country’s bias.
From Los Angeles Times ● Jul. 15, 2026
He is the loudest possible proof that you do not need a gun to be the bravest man on the hill.
From Salon ● Jul. 15, 2026
The proof was in Maya-Jade standing in front of him with her clipboard.
From "Not Nothing" by Gayle Forman
Hotel managers learned that, despite jokes about -proof industries, relying heavily on a Western male clientele was unwise at a time when the United States and Europe were buffeted by recession.
From New York Times ● Sep. 16, 2010
“We’re on the path to achieve this transition from small proofs of concept to large enterprise deals,” Baratz said.
From Barron's ● Jan. 27, 2026
Her goal is to build an “AI mathematician,” capable of reasoning through known problems, finding new ones and validating its work through formal proofs.
From The Wall Street Journal ● Dec. 4, 2025
I always thought page proofs were pure torture.
From Los Angeles Times ● Nov. 4, 2025
I think that if we assume our animals understand us, or if we assume things that without proofs that that can cause its own damage.
From Salon ● Nov. 2, 2025
Technical proofs have to be constructed by the advocate.
From "The Invention of Science" by David Wootton
Campbell ran Ben’s Bread solo for six of the last eight years, sometimes speeding between multiple kitchens across the city to get everything proofed, baked and packaged.
From Seattle Times ● Jun. 22, 2023
He wants to see the new law "contain future proofed regulation", so it also requires the same admission for altered videos, and any other tech developments.
From BBC ● May 14, 2023
Tip the proofed dough out to the center of the parchment paper so the seam is facing down.
From Salon ● Apr. 14, 2022
Apparently, the host explained that she had "stupid proofed" the room – not just by using the notes but also making hardware adjustments.
From Fox News ● Dec. 21, 2021
There was not a piece of armour proofed in Europe but what Unde Dap had a theory about it He was furious with the new Gothic style, with its ridges and scallop-patterns and fluting.
From "The Once and Future King" by T. H. White
I can imagine Swifties swapping starters instead of friendship bracelets, posting Instagram threads of rainbow-hued loaves with song lyrics as labels, hosting listening-party bake nights and turning proofing schedules into a kind of communal obsession.
From Salon ● Aug. 31, 2025
Maintenance worker Darren Pardoe had been bird proofing houses in Porthleven when he stopped at a pub for a coffee on 3 June.
From BBC ● Jun. 14, 2025
The Barrett campaign described this as a simple proofing screw-up and said that the team had been working off of a template used ahead of the state’s Aug. 6 primary.
From Slate ● Oct. 19, 2024
The monument park is a “dream project” that Halsey has been “visioning, proofing and prototyping” ever since she studied architecture at El Camino community college in Torrance, Halsey said in the announcement Monday.
From Los Angeles Times ● May 20, 2024
The only similarity between the rest of the town and the church is the small windows covered with iron bars, but the shambler proofing is barely noticeable on such an impressive building.
From "Dread Nation" by Justina Ireland
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
