The Collaborative International Dictionary of English v.0.48:

Heel \Heel\, n. [OE. hele, heele, AS. h[=e]la, perh. for
   h[=o]hila, fr. AS. h[=o]h heel (cf. Hough); but cf. D.
   hiel, OFries. heila, h[=e]la, Icel. h[ae]ll, Dan. h[ae]l, Sw.
   h[aum]l, and L. calx. [root]12. Cf. Inculcate.]
   1. The hinder part of the foot; sometimes, the whole foot; --
      in man or quadrupeds.
      [1913 Webster]

            He [the stag] calls to mind his strength and then
            his speed,
            His winged heels and then his armed head. --Denham.
      [1913 Webster]

   2. The hinder part of any covering for the foot, as of a
      shoe, sock, etc.; specif., a solid part projecting
      downward from the hinder part of the sole of a boot or
      shoe.
      [1913 Webster]

   3. The latter or remaining part of anything; the closing or
      concluding part. "The heel of a hunt." --A. Trollope. "The
      heel of the white loaf." --Sir W. Scott.
      [1913 Webster]

   4. Anything regarded as like a human heel in shape; a
      protuberance; a knob.
      [1913 Webster]

   5. The part of a thing corresponding in position to the human
      heel; the lower part, or part on which a thing rests;
      especially:
      (a) (Naut.) The after end of a ship's keel.
      (b) (Naut.) The lower end of a mast, a boom, the bowsprit,
          the sternpost, etc.
      (c) (Mil.) In a small arm, the corner of the but which is
          upwards in the firing position.
      (d) (Mil.) The uppermost part of the blade of a sword,
          next to the hilt.
      (e) The part of any tool next the tang or handle; as, the
          heel of a scythe.
          [1913 Webster]

   6. (Man.) Management by the heel, especially the spurred
      heel; as, the horse understands the heel well.
      [1913 Webster]

   7. (Arch.)
      (a) The lower end of a timber in a frame, as a post or
          rafter. In the United States, specif., the obtuse
          angle of the lower end of a rafter set sloping.
      (b) A cyma reversa; -- so called by workmen. --Gwilt.
          [1913 Webster]

   8. (Golf) The part of the face of the club head nearest the
      shaft.
      [Webster 1913 Suppl.]

   9. In a carding machine, the part of a flat nearest the
      cylinder.
      [Webster 1913 Suppl.]

   Heel chain (Naut.), a chain passing from the bowsprit cap
      around the heel of the jib boom.

   Heel plate, the butt plate of a gun.

   Heel of a rafter. (Arch.) See Heel, n., 7.

   Heel ring, a ring for fastening a scythe blade to the
      snath.

   Neck and heels, the whole body. (Colloq.)

   To be at the heels of, to pursue closely; to follow hard;
      as, hungry want is at my heels. --Otway.

   To be down at the heel, to be slovenly or in a poor plight.


   To be out at the heels, to have on stockings that are worn
      out; hence, to be shabby, or in a poor plight. --Shak.

   To cool the heels. See under Cool.

   To go heels over head, to turn over so as to bring the
      heels uppermost; hence, to move in a inconsiderate, or
      rash, manner.

   To have the heels of, to outrun.

   To lay by the heels, to fetter; to shackle; to imprison.
      --Shak. --Addison.

   To show the heels, to flee; to run from.

   To take to the heels, to flee; to betake to flight.

   To throw up another's heels, to trip him. --Bunyan.

   To tread upon one's heels, to follow closely. --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Heel \Heel\ (h[=e]l), v. i. [OE. helden to lean, incline, AS.
   heldan, hyldan; akin to Icel. halla, Dan. helde, Sw.
   h[aum]lla to tilt, pour, and perh. to E. hill.] (Naut.)
   To lean or tip to one side, as a ship; as, the ship heels
   aport; the boat heeled over when the squall struck it.
   [1913 Webster]

   Heeling error (Naut.), a deviation of the compass caused by
      the heeling of an iron vessel to one side or the other.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Heel \Heel\, v. t. [imp. & p. p. Heeled; p. pr. & vb. n.
   Heeling.]
   1. To perform by the use of the heels, as in dancing,
      running, and the like. [R.]
      [1913 Webster]

            I cannot sing,
            Nor heel the high lavolt.             --Shak.
      [1913 Webster]

   2. To add a heel to; as, to heel a shoe.
      [1913 Webster]

   3. To arm with a gaff, as a cock for fighting.
      [1913 Webster]

   4. (Golf) To hit (the ball) with the heel of the club.
      [Webster 1913 Suppl.]

   5. (Football) To make (a fair catch) standing with one foot
      advanced, the heel on the ground and the toe up.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

heel
    n 1: the bottom of a shoe or boot; the back part of a shoe or
         boot that touches the ground and provides elevation
    2: the back part of the human foot
    3: someone who is morally reprehensible; "you dirty dog" [syn:
       cad, bounder, blackguard, dog, hound, heel]
    4: one of the crusty ends of a loaf of bread
    5: the lower end of a ship's mast
    6: (golf) the part of the clubhead where it joins the shaft
    v 1: tilt to one side; "The balloon heeled over"; "the wind made
         the vessel heel"; "The ship listed to starboard" [syn:
         list, heel]
    2: follow at the heels of a person
    3: perform with the heels; "heel that dance"
    4: strike with the heel of the club; "heel a golf ball"
    5: put a new heel on; "heel shoes" [syn: heel, reheel]

Moby Thesaurus II by Grady Ward, 1.0:

209 Moby Thesaurus words for "heel":
   SOB, accouter, afterpart, afterpiece, appoint, arch, arm, back,
   back door, back seat, back side, balance, bastard, bear off, bedog,
   behind, bend, blackguard, bounder, branch off, breech, broke,
   bugger, cad, cant, careen, change the bearing, chase, clubfoot,
   come about, come after, come behind, counter, creep, crust, curve,
   depart from, destitute, detour, deviate, digit, digress, divagate,
   divaricate, diverge, dog, dowdy, dress, end, equip, escape,
   extremity, fantail, fart, fetch about, fetlock, fit, fit out,
   fit up, flee, fly the coop, follow, foot, forefoot, forepaw,
   furnish, gear, go about, go after, go behind, harefoot, hind end,
   hind part, hindhead, hood, hoof, hooligan, hound, impoverished,
   in straitened circumstances, incline, instep, jerk, knave,
   lay down, lean, lean over, leavings, lie along, list, louse,
   lowlife, man, meanie, miscreant, mother, move behind, munition,
   occiput, out at elbows, outfit, pad, pastern, patte, paw,
   pedal extremity, pedes, pes, philanderer, pied, pill, pivot,
   pivot about, poop, poor, posterior, postern, prepare, pug, pursue,
   put about, rascal, rat, rear, rear end, rearward, recline,
   remainder, remains, remnant, residual, residue, residuum, rest,
   reverse, rig, rig out, rig up, rind, rogue, rotter, round,
   rudderpost, run away, run off, run-down, scamp, scoundrel, seedy,
   shabby, shadow, sheer, shift, shit, shithead, shitheel, slope,
   slovenly, sod, sole, spin, splayfoot, split, staff, stern,
   stinkard, stinker, strapped, string along, stump, swerve, swine,
   swing, swing round, swivel, tack, tag, tag after, tag along, tail,
   tail end, tailgate, tailpiece, take flight, tilt, tip, toe, tootsy,
   trail, trail after, tread close upon, trend, trotter, turd, turn,
   turn about, turn around, turn aside, turn out, turn round,
   turn tail, ungula, vary, veer, veer around, wheel, wheel about,
   whirl, worm