Source : Webster's Revised Unabridged Dictionary (1913)

Lock \Lock\, n. [AS. locc; akin to D. lok, G. locke, OHG. loc,
   Icel. lokkr, and perh. to Gr. ? to bend, twist.]
   A tuft of hair; a flock or small quantity of wool, hay, or
   other like substance; a tress or ringlet of hair.

         These gray locks, the pursuivants of death. --Shak.

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}.

Lock \Lock\, v. t. [imp. & p. p. {Locked}; p. pr. & vb. n.
   {Locking}.]
   1. To fasten with a lock, or as with a lock; to make fast; to
      prevent free movement of; as, to lock a door, a carriage
      wheel, a river, etc.

   2. To prevent ingress or access to, or exit from, by
      fastening the lock or locks of; -- often with up; as, to
      lock or lock up, a house, jail, room, trunk. etc.

   3. To fasten in or out, or to make secure by means of, or as
      with, locks; to confine, or to shut in or out -- often
      with up; as, to lock one's self in a room; to lock up the
      prisoners; to lock up one's silver; to lock intruders out
      of the house; to lock money into a vault; to lock a child
      in one's arms; to lock a secret in one's breast.

   4. To link together; to clasp closely; as, to lock arms. ``
      Lock hand in hand.'' --Shak.

   5. (Canals) To furnish with locks; also, to raise or lower (a
      boat) in a lock.

   6. (Fencing) To seize, as the sword arm of an antagonist, by
      turning the left arm around it, to disarm him.

Lock \Lock\, v. i.
   To become fast, as by means of a lock or by interlacing; as,
   the door locks close.

         When it locked none might through it pass. --Spenser.

   {To lock into}, to fit or slide into; as, they lock into each
      other. --Boyle.

Source : WordNet®

lock
     v 1: fasten with a lock; "lock the bike to the fence" [ant: {unlock},
           {unlock}]
     2: keep engaged; "engaged the gears" [syn: {engage}, {mesh}, {operate}]
        [ant: {disengage}]
     3: become rigid or immoveable; "The therapist noticed that the
        patient's knees tended to lock in this exercise" [ant: {unlock}]
     4: hold in a locking position; "He locked his hands around her
        neck" [syn: {interlock}, {interlace}]
     5: become engaged or intermeshed with one another; "They were
        locked in embrace" [syn: {interlock}]
     6: hold fast (in a certain state); "He was locked in a laughing
        fit"
     7: place in a place where something cannot be removed or
        someone cannot escape; "The parents locked her daughter up
        for the weekend"; "She locked her jewels in the safe"
        [syn: {lock in}, {lock away}, {put away}, {shut up}, {shut
        away}, {lock up}]
     8: pass by means through a lock in a waterway
     9: build locks in order to facilitate the navigation of vessels

lock
     n 1: a fastener fitted to a door or drawer to keep it firmly
          closed
     2: a strand or cluster of hair [syn: {curl}, {ringlet}, {whorl}]
     3: a mechanism that detonates the charge of a gun
     4: enclosure consisting of a section of canal that can be
        closed to control the water level; used to raise or lower
        vessels that pass through it [syn: {lock chamber}]
     5: a restraint incorporated into the ignition switch to prevent
        the use of a vehicle by persons who do not have the key
        [syn: {ignition lock}]
     6: any wrestling hold in which some part of the opponent's body
        is twisted or pressured