The Collaborative International Dictionary of English v.0.48:

Crossette \Cros*sette"\ (kr?s-s?t`), n. [F., dim. of crosse. See
   Crosier.] (Arch.)
   (a) A return in one of the corners of the architrave of a
       door or window; -- called also ancon, ear, elbow.
   (b) The shoulder of a joggled keystone.
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Elbow \El"bow\, n. [AS. elboga, elnboga (akin to D. elleboga,
   OHG. elinbogo, G. ellbogen, ellenbogen, Icel. ?lnbogi; prop.;
   arm-bend); eln ell (orig., forearm) + boga a bending. See 1st
   Ell, and 4th Bow.]
   1. The joint or bend of the arm; the outer curve in the
      middle of the arm when bent.
      [1913 Webster]

            Her arms to the elbows naked.         --R. of
                                                  Gloucester.
      [1913 Webster]

   2. Any turn or bend like that of the elbow, in a wall,
      building, and the like; a sudden turn in a line of coast
      or course of a river; also, an angular or jointed part of
      any structure, as the raised arm of a chair or sofa, or a
      short pipe fitting, turning at an angle or bent.
      [1913 Webster]

   3. (Arch.) A sharp angle in any surface of wainscoting or
      other woodwork; the upright sides which flank any paneled
      work, as the sides of windows, where the jamb makes an
      elbow with the window back. --Gwilt.
      [1913 Webster]

   Note: Elbow is used adjectively or as part of a compound, to
         denote something shaped like, or acting like, an elbow;
         as, elbow joint; elbow tongs or elbow-tongs; elbowroom,
         elbow-room, or elbow room.
         [1913 Webster]

   At the elbow, very near; at hand.

   Elbow grease, energetic application of force in manual
      labor. [Low]

   Elbow in the hawse (Naut.), the twisting together of two
      cables by which a vessel rides at anchor, caused by
      swinging completely round once. --Totten.

   Elbow scissors (Surg.), scissors bent in the blade or shank
      for convenience in cutting. --Knight.

   Out at elbow, with coat worn through at the elbows; shabby;
      in needy circumstances.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Elbow \El"bow\, v. i.
   1. To jut into an angle; to project or to bend after the
      manner of an elbow.
      [1913 Webster]

   2. To push rudely along; to elbow one's way. "Purseproud,
      elbowing Insolence." --Grainger.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Elbow \El"bow\, v. t. [imp. & p. p. Elbowed; p. pr. & vb. n.
   Elbowing.]
   To push or hit with the elbow, as when one pushes by another.
   [1913 Webster]

         They [the Dutch] would elbow our own aldermen off the
         Royal Exchange.                          --Macaulay.
   [1913 Webster]

   To elbow one's way, to force one's way by pushing with the
      elbows; as, to elbow one's way through a crowd.
      [1913 Webster]

WordNet (r) 3.0 (2006):

elbow
    n 1: hinge joint between the forearm and upper arm and the
         corresponding joint in the forelimb of a quadruped [syn:
         elbow, elbow joint, human elbow, cubitus, cubital
         joint, articulatio cubiti]
    2: a sharp bend in a road or river
    3: a length of pipe with a sharp bend in it
    4: the part of a sleeve that covers the elbow joint; "his coat
       had patches over the elbows"
    5: the joint of a mammal or bird that corresponds to the human
       elbow
    v 1: push one's way with the elbows
    2: shove one's elbow into another person's ribs