Definitions:
evidence or argument establishing a fact or the truth of a statement

a trial impression of a page, taken from type or film and used for making corrections before final printing.

the strength of distilled alcoholic spirits, relative to proof spirit taken as a standard of 100

a test or trial of something.

a trial or a civil case before a judge without a jury.

able to withstand something damaging; resistant

denoting a trial impression of a page or printed work

make (fabric) waterproof

make a proof of (a printed work, engraving, etc.)

activate (yeast) by the addition of liquid