Source : Webster's Revised Unabridged Dictionary (1913)

Lock \Lock\, n. [AS. loc inclosure, an inclosed place, the
   fastening of a door, fr. l[=u]can to lock, fasten; akin to
   OS. l[=u]kan (in comp.), D. luiken, OHG. l[=u]hhan, Icel.
   l?ka, Goth. l[=u]kan (in comp.); cf. Skr. ruj to break. Cf.
   {Locket}.]
   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.
      --Dryden.

   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. --Milton.

   {Detector lock}, a lock containing a contrivance for showing
      whether it as has been tampered with.

   {Lock bay} (Canals), the body of water in a lock chamber.

   {Lock chamber}, the inclosed space between the gates of a
      canal lock.

   {Lock nut}. See {Check nut}, under {Check}.

   {Lock plate}, a plate to which the mechanism of a gunlock is
      attached.

   {Lock rail} (Arch.), in ordinary paneled doors, the rail
      nearest the lock.

   {Lock rand} (Masonry), a range of bond stone. --Knight.

   {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}.

Mortise \Mor"tise\, n. [F. mortaise; cf. Sp. mortaja, Ar.
   murtazz fixed, or W. mortais, Ir. mortis, moirtis, Gael.
   moirteis.]
   A cavity cut into a piece of timber, or other material, to
   receive something (as the end of another piece) made to fit
   it, and called a tenon.

   {Mortise and tenon} (Carp.), made with a mortise and tenon;
      joined or united by means of a mortise and tenon; -- used
      adjectively.

   {Mortise joint}, a joint made by a mortise and tenon.

   {Mortise lock}. See under {Lock}.

   {Mortise wheel}, a cast-iron wheel, with wooden clogs
      inserted in mortises on its face or edge; -- also called
      {mortise gear}, and {core gear}.