noun

1. the act or process of proving; a testing or trying of something
2. anything serving or tending to establish the truth of something, or to convince one of its truth; conclusive evidence
3. the establishment of the truth of something to work on the proof of a theory
4. a test or trial of the truth, worth, quality, etc. of something the proof of the pudding is in the eating
5. the quality or condition of having been tested or proved
6. Obsolete tested or proved strength, as of armor
7. 1. the relative strength of an alcoholic liquor with reference to the arbitrary standard for proof spirit
   2. this standard, taken as 100 proof
8. Engraving a trial impression taken from a plate, block, or stone
9. Law all the facts, admissions, and conclusions drawn from evidence which together operate to determine a verdict or judgment
10. Math. a process for checking the correctness of a computation, as, in a subtraction problem, by adding the difference to the subtrahend to get the minuend
11. Numismatics any of a limited number of coins of a new issue, struck with special care
12. Photog. a trial print of a negative
13. Printing an impression of composed type taken for checking errors and making changes

Etymology: ME profe < OFr prueve < LL proba < L probare: see probe

adjective

1. of tested and proved strength
2. impervious or invulnerable to; able to resist, withstand, etc.: with against proof against criticism
3. used in proving or testing
4. of standard strength: said of alcoholic liquors

transitive verb

1. to make a proof of
2. to make resistant or impervious to something
3. proofread