- proof
- 1
/pru:f/ noun
1 (C, U) facts, information, documents etc that prove something is true(+ of): Bring a passport as proof of identity. (+ (that)): Do you have any proof that this man stole your bag? | conclusive proof (=that cannot be doubted) | proof positive (=definite proof)2 (C) technical a printed copy of a piece of writing used to find and remove mistakes before the final printing is done: Can you check these proofs?3 (C) a photograph that is used as a test copy before an official copy is made4 (C)5a) a test in mathematics of the correctness of a calculationb) a list of reasons that shows a theorem (=statement) in geometry to be true6 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 it7 (U) technical the standard strength of some kinds of alcoholic drink compared with that of proof spirit: This gin is 15% under proof.8 put sth to the proof to test the quality or strength of something2 adjective1 waterproof/bulletproof etc something that is waterproof etc will not let water etc through it or into it: a soundproof room2 child-proof/vandal-proof not easily affected or damaged by someone or something: a child-proof latch on the cupboard3 be proof against to be too strong or good to be affected by something bad: a faith that is proof against temptation4 30% proof/40% proof etc BrE, also 30 proof/40 proof etc AmE whisky, bourbon etc that has a particular proof contains a specific amount of alcohol3 verb (transitive usually passive) to treat a material with a substance in order to protect it against water, oil etc (+ against): climbing gear proofed against water
Longman dictionary of contemporary English. 2004.