1. Anything that fastens; specifically, a fastening, as for a door, a lid, a trunk, a drawer, and the like, in which a bolt is moved by a key so as to hold or to release the thing fastened.
2. A fastening together or interlacing; a closing of one thing upon another; a state of being fixed or immovable. Albemarle Street closed by a lock of carriages. (De Quincey)
3. A place from which egress is prevented, as by a lock.
4. The barrier or works which confine the water of a stream or canal.
5. An inclosure in a canal with gates at each end, used in raising or lowering boats as they pass from one level to another; called also lift lock.
6. That part or apparatus of a firearm by which the charge is exploded; as, a matchlock, flintlock, percussion lock, etc.
7. A device for keeping a wheel from turning.
8. A grapple in wrestling. Detector lock, a lock containing a contrivance for showing whether it as has been tampered with. Lock bay, a range of bond stone. Mortise lock, a door lock inserted in a mortise. Rim lock, a lock fastened to the face of a door, thus differing from a mortise lock.
Origin: as. Loc inclosure, an inclosed place, the fastening of a door, fr. Lucan to lock, fasten; akin to os. Lukan (in comp), D. Luiken, OHG. Luhhan, Icel. Lka, goth. Lukan (in comp); cf. Skr. Ruj to break. Cf. Locket.