proof

verb

proofed; proofing; proofs

transitive verb

1

a

: to make or take a proof or test of

b

: proofread

2

: to give a resistant quality to

3

: to activate (yeast) by mixing with water and sometimes sugar or milk

proofer noun

Examples of proof in a Sentence

She proofed the story carefully.

Recent Examples on the Web

For example, the upfront cost of home improvements that could reduce a home’s flood exposure, such as elevating the home or flood-proofing the property, can be too high for many people to afford, but assistance programs can help. —Ivis García, The Conversation, 1 June 2026

But this year’s Indy 500 didn’t miss equaling last year’s rating by much, giving IndyCar and Indianapolis Motor Speedway officials proof that the series has continued momentum. —Bruce Martin, Forbes.com, 28 May 2026

After proofing, they are broken into small servings, stuffed with pork and steamed. —Amy Drew Thompson, The Orlando Sentinel, 27 May 2026

Some even have temperatures that go low enough for dehydrating, proofing dough and fermenting. —Bestreviews, Mercury News, 20 May 2026

Word History

First Known Use

circa 1699, in the meaning defined at sense 1a

Phrases Containing proof

• burden of proof
• living proof
• proof of concept
• proof of purchase
• proof positive
• proof spirit
• reproduction proof
• the proof is in the pudding
• the proof of the pudding is in the eating
• veto-proof

Rhymes for proof

• goof
• hoof
• kloof
• poof
• roof
• spoof
• woof
• aloof
• behoof
• disproof
• flameproof
• foolproof

Kids Definition

proof

1 of 3 noun

ˈprüf 

1

a

: evidence of truth or correctness

gave proof of her statement

b

: an act or process of showing or finding out that something is true especially by reasoning or by experiment

a proof that the theorem is true

put a theory to the proof

2

a

: a copy (as of something set in type) taken for study and correction

b

: a test print made from a photographic negative

proof

2 of 3 adjective

: designed or made to prevent or keep out something that could be harmful

this lock is proof against tampering

—often used in compounds

waterproof

proof

3 of 3 verb

: to activate (yeast) by mixing with water

Legal Definition

proof

noun

1

: the effect of evidence sufficient to persuade a reasonable person that a particular fact exists see also evidence

2

: the establishment or persuasion by evidence that a particular fact exists see also burden of proof

3

: something (as evidence) that proves or tends to prove the existence of a particular fact see also clear and convincing, preponderance of the evidence, reasonable doubt, standard of proof compare allegation, argument

4

: probate sense 1a

Etymology

alteration of Middle English preove, from Old French preuve, from Late Latin proba, from Latin probare to prove