Proof that a hostage is still alive.

plural of India proof

(historical) A high-quality proof taken from engraved plates by means of India paper.

(humorous) Of a play or a dramatic part: sufficiently good that it should be able to succeed even with an inferior cast.

A small conductor attached to an insulated handle used to transfer electrical charge to a measuring instrument.

Overproof; containing more alcohol than proof spirit.

plural of proof mark

Of a play, etc.: resistant to negative responses from the audience; popular with everybody.

A building fitted for proving the barrels of firearms.

plural of proof house