Date: 1200-1300
Language: Old French
Origin: preuve, from Late Latin proba, from Latin probare; PROBE2


1 noun
proof1 S2 W3


[uncountable and countable] facts, information, documents etc that prove something is true
proof of
proof of the existence of life on other planets
This latest interview was further proof of how good at her job Cara was.
proof of purchase/ownership/identity
Do you have any proof of purchase? (=something to prove that you bought and paid for something)
You'll need your passport as proof of identity.
proof (that)
Do you have any proof that this man stole your bag?
There is no proof that the document is authentic.
Laboratory tests gave conclusive proof that the meat presents no risk to human health.
He's living proof (=his experience or life shows it is true) that footballers can still play at the highest level into their late thirties.
proof positive (=definite proof that cannot be doubted)
We received 800 applications last year, proof positive that the college is highly regarded by parents and students.
burden/onus of proof law (=used to say who has to show that something is true or not in a legal case)
The burden of proof lies on the defendant.


[countable usually plural] technicalTCN a copy of a piece of writing or a photograph that is checked carefully before the final printing is done:
Can you check these proofs?


a) HM a test in mathematics of whether a calculation is correct
b) HM a list of reasons that shows a theorem (=statement) in geometry to be true

the proof of the pudding (is in the eating)

used to say that you can only know whether something is good or bad after you have tried it


[uncountable]DFD a measurement of the strength of some types of alcoholic drink, especially spirits :
70% proof vodka (=that contains 70% pure alcohol) British English
70 proof vodka (=that contains 35% pure alcohol) American English

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