Key

Key, kē, n. an instrument for shutting or opening a lock: that by which something is screwed or turned: the middle stone of an arch: a piece of wood let into another piece crosswise to prevent warping: (mus.) one of the small levers in musical instruments for producing notes: the fundamental note of a piece of music: that which explains a mystery: a book containing answers to exercises, &c.—ns. Key′board, the keys or levers in a piano or organ arranged along a flat board; Key′-bū′gle, a bugle with keys, having a compass of two octaves including semitones.—adjs. Key′-cold (Shak.), cold as a key, lifeless; Keyed, furnished with keys, as a musical instrument: set to a particular key, as a tune.—ns. Key′hole, the hole in which a key of a door, &c., is inserted; Key′note, the key or fundamental note of a piece of music; any central principle or controlling thought; Key′-pin, the pivot on which a pipe-key turns: a pin serving as fulcrum for a key of an organ, &c.; Key′-plate, the escutcheon around a keyhole; Key′ring, a ring for holding a bunch of keys; Key′-seat, a groove for receiving a key, to prevent one piece of machinery from turning on another; Key′stone, the stone at the apex of an arch: the chief element in any system.—Have the key of the street (coll.), to be locked out: to be homeless; Power of the keys, the power to loose and bind, to administer ecclesiastical discipline—a special authority conferred by Christ on Peter (Matt. xvi. 19), or Peter in conjunction with the other apostles, and claimed by the popes as the alleged successors to St Peter. Others explain it as belonging only to the apostles themselves, as descending to the bishops and clergy of the Christian Church, or as belonging to all Christ's disciples alike. [A.S. cæg, a key.]