1) N-VAR: oft N of n, N that Proof is a fact, argument, or piece of evidence which shows that something is definitely true or definitely exists.

You have to have proof of residence in the state of Texas, such as a Texas ID card...

This is not necessarily proof that he is wrong...

Economists have been concerned with establishing proofs for their arguments.

2) N-COUNT: usu pl, oft N of n In publishing, the proofs of a book, magazine, or article are a first copy of it that is printed so that mistakes can be corrected before more copies are printed and published.

I'm correcting the proofs of the Spanish edition right now.

Proof is also an adjective. uncorrected proof copy of the book.

3) ADJ: amount ADJ Proof is used after a number of degrees or a percentage, when indicating the strength of a strong alcoholic drink such as whisky.

...a glass of Wild Turkey bourbon: 101 degrees proof.

4) ADJ: v-link ADJ against n If something or someone is proof against a particular thing, they cannot be damaged, harmed, or affected by it. [WRITTEN]

The fortress was proof against the techniques of attack then in use...

His papers were proof against all but the most expert of scrutinies.

5) PHRASE: usu v-link PHR, oft PHR that, PHR of n If you say that someone is living proof of something, you mean that their actions or personal qualities show that a particular fact is true or that a particular quality exists.

He is living proof that some players just get better with age.

6) PHRASE: usu v-link PHR, oft PHR that, PHR of n To be proof positive of a particular fact or quality means to be evidence that it is true or that it exists. [FORMAL]

The Windermere Golf Club is proof positive that golf and ecology can co-exist in perfect harmony.

7) burden of proofsee burden
the proof of the pudding is in the eatingsee pudding

English dictionary. 2008.