I. proof 1 S3 W3 /pruːf/ BrE AmE noun
[ Word Family: verb : ↑ prove ≠ ↑ disprove ; noun : ↑ proof ; adjective : ↑ proven ≠ ↑ unproven ]
[ Date: 1200-1300 ; Language: Old French ; Origin: preuve , from Late Latin proba , from Latin probare ; ⇨ ↑ probe 2 ]
1 . EVIDENCE [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 (that)
Do you have any proof that this man stole your bag?
There is no proof that the document is authentic.
2 . COPY [countable usually plural] technical 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?
3 . MATHEMATICS [countable]
a) a test in mathematics of whether a calculation is correct
b) a list of reasons that shows a ↑ theorem (=statement) in ↑ geometry to be true
4 . 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
5 . ALCOHOL [uncountable] a measurement of the strength of some types of alcoholic drink, especially ↑ spirit s :
70% proof vodka (=that contains 70% pure alcohol) British English
70 proof vodka (=that contains 35% pure alcohol) American English
• • •
COLLOCATIONS
■ verbs
▪ have proof
The newspaper claimed it had proof that I worked for the CIA.
▪ provide/give proof
You will be required to provide proof of your identity.
▪ need proof
He needed proof to back up those allegations.
▪ there is proof
There is now proof that giant squid do exist.
■ adjectives
▪ further proof (=additional proof)
He showed his driving licence as further proof of his identity.
▪ scientific proof
They say they have scientific proof that the treatment works.
▪ living proof (=someone whose existence or experience proves something)
She is living proof that stress need not necessarily be ageing.
▪ clear proof
His indecision is clear proof of his inability to handle the situation.
▪ conclusive/tangible proof (=definite proof)
There is no conclusive proof that your son is dead.
■ phrases
▪ proof of identity (=something that proves who you are)
Do you have any proof of identity, such as a passport?
▪ proof of purchase (=something that proves you bought something from a particular place)
We will give a refund only if proof of purchase is provided.
▪ proof of ownership
Take photos of anything unusual you own as proof of ownership.
▪ proof positive (=definite proof that cannot be doubted)
Here is proof positive that she's wrong.
▪ the burden/onus of proof law (=the need to prove that you are right in a legal case)
The burden of proof is on the prosecution.
II. proof 2 BrE AmE adjective
be proof against something literary to be too strong or good to be affected by something bad:
Their defences are proof against most weapons.
III. proof 3 BrE AmE verb [transitive] British English
1 . [usually passive] to treat a material with a substance in order to protect it against water, oil etc
proof something against something
climbing gear proofed against water
2 . to proofread something