# proof

Pronunciation: say "PROOF" US /pɹuf/, UK /pɹuːf/

## Noun

1. Evidence, an argument or a document that shows, or helps to show, that something is true.
   - Simple: Facts, information or a paper that show something is true.
   - _The prosecution offered fingerprints as proof of the defendant's presence at the scene._
   - _Despite years of searching, no one has found proof that the treasure exists._
2. A sequence of statements, each an axiom, an assumption, a previously demonstrated result, or a logical consequence of earlier statements, ending with the statement to be established.
   - Simple: A set of steps that shows, one by one, why a math statement must be true.
   - _Euclid's proof of the infinitude of primes is admired for its elegance._
   - _She spent the weekend checking every step of the proof for errors._
4. A trial impression of typeset or printed material, taken so errors can be examined and corrected before final printing.
   - Simple: A test copy of a printed page, made so people can find mistakes before printing.
   - _The designer sent the client a proof of the wedding invitation for approval._
   - _Compositors once pulled proofs by hand to check each freshly set page._
8. A measure of the alcohol content of liquor; in the United States, the proof is twice the percentage of alcohol by volume. *(US)*
   - Simple: A number that tells you how strong an alcoholic drink is.
   - _Bartenders sometimes check the proof before using a spirit in flaming cocktails._
   - _The distillery raised the proof of its flagship bourbon from 90 to 100._
5. The testing of something to find out whether it is true, accurate, strong, or reliable: the trial itself, not the evidence or argument it produces, as in put to the proof.
   - Simple: A test or check to find out whether something is true, correct, strong, or reliable.
   - _The long, hard winter put their young friendship to the proof._
   - _The proof of the pudding is in the eating, as the old saying goes._

## Adjective

3. Firm or successful in resisting; able to withstand a particular force or influence.
   - Simple: Strong enough to resist something and not be harmed by it.
   - _The fortress walls were proof against cannon fire of the period._
   - _No politician is entirely proof against flattery._
10. Describing liquor as being of a given standard strength on the proof scale, as in proof spirit or 100-proof rum.
   - Simple: Having a certain level of alcohol, shown by a number.
   - _The distillery's signature bourbon is 90 proof but smooth enough to sip neat._
   - _Anything 120 proof or higher will overwhelm the other flavors in a cocktail._

## Verb

6. To treat something so as to make it resistant, especially to water.
   - Simple: To treat something so that water or other things cannot easily get in or harm it.
   - _The manufacturer proofs each jacket against rain before shipping._
   - _Climbers proof their canvas packs with wax to survive wet conditions._
9. In baking, to let shaped yeast dough rise before it goes in the oven, or to test yeast in warm water to check that it is still active.
   - Simple: In baking, to leave bread dough to rise before baking, or to check that yeast is still alive.
   - _Bakers proof the shaped loaves until they nearly double in size._
   - _She proofed the baguettes in a cloth-lined basket before scoring them._
7. To read written or printed material in order to find and correct errors; to proofread. *(colloquial)*
   - Simple: To read something carefully to find and fix mistakes.
   - _An intern proofs every press release before it goes out._
   - _He used to proof for a legal publisher, catching errors others missed._

## Noun

11. The quality or state of having been tested and proved; firmness or hardness that resists impression or does not yield to force. *(archaic)*
   - Simple: Hardness or strength that nothing can break through or press into.
12. Armor of tried and excellent quality, considered impenetrable; properly called armor of proof. *(obsolete)*
   - Simple: Strong armor that people believed weapons could not cut or break through.
13. Experience of something; direct knowledge gained by undergoing or witnessing it. *(obsolete)*
   - Simple: Knowledge of something that you gained by living through it yourself.
14. Firmness of mind; steadiness or stability of character that cannot be shaken. *(obsolete)*
   - Simple: A strong and steady mind that nothing can shake.

## Other meanings

- (noun) A limited-run, high-quality strike of a coin, originally made as a test run but now produced mainly for collectors' sets.
- (adjective) Used in proving or testing; applied to a charge, load, or sample employed to check strength or quality.
- (verb) To test-fire a firearm with a load well above its rated maximum chamber pressure, in order to establish that it can withstand pressures far beyond normal service without bursting.

## Origin

The ultimate source is Latin "probo" ("to prove"), which gave Late Latin "proba" ("a proof"); that passed through Old French "prove" into Middle English "proof." "Probe" is its doublet.

Source: DictionaryAI, https://dictionaryai.com/define/proof (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).