PROOF a.
gin.), the greatest load than can be applied to a piece, as a beam, column, etc., without straining the piece beyond the elastic limit. -- Proof sheet. See Proof, n., 5. -- Proof spirit (Chem.), a strong distilled liquor, or mixture of alcohol and water, containing not less than a standard amount of alcohol. In the U…
REIN n. 2 definitions
Hence, an instrument or means of curbing, restraining, or governing; government; restraint. "Let their eyes rove without rein." Milton. To give rein, To give the rein to, to give license to; to leave withouut restrain. -- To take the reins, to take the guidance or government; to assume control.