Lock nut

from The Collaborative International Dictionary of English v.0.48
Nut \Nut\ (n[u^]t), n. [OE. nute, note, AS. hnutu; akin to D.
   noot, G. nuss, OHG. nuz, Icel. hnot, Sw. n["o]t, Dan.
   n["o]d.]
   [1913 Webster]
   1. (Bot.) The fruit of certain trees and shrubs (as of the
      almond, walnut, hickory, beech, filbert, etc.), consisting
      of a hard and indehiscent shell inclosing a kernel.
      [1913 Webster]

   2. A perforated block (usually a small piece of metal),
      provided with an internal or female screw thread, used on
      a bolt, or screw, for tightening or holding something, or
      for transmitting motion. See Illust. of 1st {Bolt}.
      [1913 Webster]

   3. The tumbler of a gunlock. --Knight.
      [1913 Webster]

   4. (Naut.) A projection on each side of the shank of an
      anchor, to secure the stock in place.
      [1913 Webster]

   5. pl. Testicles. [vulgar slang]
      [PJC]

   {Check nut}, {Jam nut}, {Lock nut}, a nut which is screwed up
      tightly against another nut on the same bolt or screw, in
      order to prevent accidental unscrewing of the first nut.
      

   {Nut buoy}. See under {Buoy}.

   {Nut coal}, screened coal of a size smaller than stove coal
      and larger than pea coal; -- called also {chestnut coal}.
      

   {Nut crab} (Zool.), any leucosoid crab of the genus {Ebalia}
      as, {Ebalia tuberosa} of Europe.

   {Nut grass} (Bot.), See {nut grass} in the vocabulary.

   {Nut lock}, a device, as a metal plate bent up at the
      corners, to prevent a nut from becoming unscrewed, as by
      jarring.

   {Nut pine}. (Bot.) See under {Pine}.

   {Nut rush} (Bot.), a genus of cyperaceous plants ({Scleria})
      having a hard bony achene. Several species are found in
      the United States and many more in tropical regions.

   {Nut tree}, a tree that bears nuts.

   {Nut weevil} (Zool.), any species of weevils of the genus
      {Balaninus} and other allied genera, which in the larval
      state live in nuts.
      [1913 Webster]
    
from The Collaborative International Dictionary of English v.0.48
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[=u]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.
      [1913 Webster]

   2. A fastening together or interlacing; a closing of one
      thing upon another; a state of being fixed or immovable.
      [1913 Webster]

            Albemarle Street closed by a lock of carriages. --De
                                                  Quincey.
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   3. A place from which egress is prevented, as by a lock.
      --Dryden.
      [1913 Webster]

   4. The barrier or works which confine the water of a stream
      or canal.
      [1913 Webster]

   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}.
      [1913 Webster]

   6. That part or apparatus of a firearm by which the charge is
      exploded; as, a matchlock, flintlock, percussion lock,
      etc.
      [1913 Webster]

   7. A device for keeping a wheel from turning.
      [1913 Webster]

   8. A grapple in wrestling. --Milton.
      [1913 Webster]

   {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}.
      [1913 Webster]
    
from The Collaborative International Dictionary of English v.0.48
locknut \locknut\, lock nut \lock nut\n.
   a supplementary nut that is screwed down on a primary nut to
   prevent it from loosening; a check nut.
   [WordNet 1.5]
    

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