Trial; essay; experiment; any effort, process or operation that ascertains truth or fact. Thus the quality of spirit is ascertained by proof; the strength of gun-powder, of fire arms and of cannon is determined by proof; the correctness of operations in arithmetic is ascertained by proof.

In law and logic, that degree of evidence which convinces the mind of the certainty of truth of fact, and produces belief. Proof is derived from personal knowledge, or from the testimony of others, or from conclusive reasoning. Proof differs from demonstration, which is applicable only to those truths of which the contrary is inconceivable. This has neither evidence of truth, nor proof sufficient to give it warrant.

Firmness or hardness that resists impression, or yields not to force; impenetrability of physical bodies; as a wall that is of proof against shot. See arms of proof.

Firmness of mind; stability not to be shaken; as a mind or virtue that is proof against the arts of seduction and the assaults of temptation.

The proof of spirits consists in little bubbles which appear on the top of the liquor after agitation, called the bead, and by the FrenchHence,

The degree of strength in spirit; as high proof; first proof; second, third or fourth proof.

In printing and engraving, a rough impression of a sheet, taken for correction; plu. proofs, not proves.

Armor sufficiently firm to resist impression. Proof is used elliptically for of proof. I have found thee . Proof against all temptation. It is sometimes followed by to, more generally by against.