n., adj., & v.
--n.
1. facts, evidence, argument, etc. establishing or helping to establish a fact (proof of their honesty; no proof that he was there).
2 Law the spoken or written evidence in a trial.
3 a demonstration or act of proving (not capable of proof; in proof of my assertion).
4 a test or trial (put them to the proof; the proof of the pudding is in the eating).
5 the standard of strength of distilled alcoholic liquors.
6 Printing a trial impression taken from type or film, used for making corrections before final printing.
7 the stages in the resolution of a mathematical or philosophical problem.
8 each of a limited number of impressions from an engraved plate before the ordinary issue is printed and usu. (in full proof before letters) before an inscription or signature is added.
9 a photographic print made for selection etc.
10 Sc. Law a trial before a judge instead of by a jury.
--adj.
1. impervious to penetration, ill effects, etc. (proof against the severest weather; his soul is proof against corruption).
2 (in comb.) able to withstand damage or destruction by a specified agent (soundproof; childproof).
3 being of proof alcoholic strength.
4 (of armour) of tried strength.
--v.tr.
1. make (something) proof, esp. make (fabric) waterproof.
2 make a proof of (a printed work, engraving, etc.).
Phrases and idioms:
above proof (of alcohol) having a stronger than standard strength. proof-plane a small flat conductor on an insulating handle for measuring the electrification of a body. proof positive absolutely certain proof. proof-sheet a sheet of printer's proof. proof spirit a mixture of alcohol and water having proof strength.
Derivatives:
proofless adj.
Etymology: ME prof prove, earlier pref etc. f. OF proeve, prueve f. LL proba f. L probare (see PROVE; adj. and sometimes v. formed app. by ellipsis f. phr. of proof proved to be impenetrable