Source : Webster's Revised Unabridged Dictionary (1913)

Burr \Burr\, v. i. [imp. & p. p. {Burred}; p. pr. & vb. n.
   {Burring}.]
   To speak with burr; to make a hoarse or guttural murmur.
   --Mrs. Browning.

Bur \Bur\, Burr \Burr\, n. [OE. burre burdock; cf. Dan. borre,
   OSw. borra, burdock, thistle; perh. akin to E. bristle (burr-
   for burz-), or perh. to F. bourre hair, wool, stuff; also,
   according to Cotgrave, ``the downe, or hairie coat, wherewith
   divers herbes, fruits, and flowers, are covered,'' fr. L.
   burrae trifles, LL. reburrus rough.]
   1. (Bot.) Any rough or prickly envelope of the seeds of
      plants, whether a pericarp, a persistent calyx, or an
      involucre, as of the chestnut and burdock. Also, any weed
      which bears burs.

            Amongst rude burs and thistles.       --Milton.

            Bur and brake and brier.              --Tennyson.

   2. The thin ridge left by a tool in cutting or shaping metal.
      See {Burr}, n., 2.

   3. A ring of iron on a lance or spear. See {Burr}, n., 4.

   4. The lobe of the ear. See {Burr}, n., 5.

   5. The sweetbread.

   6. A clinker; a partially vitrified brick.

   7. (Mech.)
      (a) A small circular saw.
      (b) A triangular chisel.
      (c) A drill with a serrated head larger than the shank; --
          used by dentists.

   8. [Cf. Gael. borr, borra, a knob, bunch.] (Zo["o]l.) The
      round knob of an antler next to a deer's head. [Commonly
      written {burr}.]

   {Bur oak} (Bot.), a useful and ornamental species of oak
      ({Quercus macrocarpa}) with ovoid acorns inclosed in deep
      cups imbricated with pointed scales. It grows in the
      Middle and Western United States, and its wood is tough,
      close-grained, and durable.

   {Bur reed} (Bot.), a plant of the genus {Sparganium}, having
      long ribbonlike leaves.

Burr \Burr\, n. [See {Bur}.] (Bot.)
   1. A prickly seed vessel. See {Bur}, 1.

   2. The thin edge or ridge left by a tool in cutting or
      shaping metal, as in turning, engraving, pressing, etc.;
      also, the rough neck left on a bullet in casting.

            The graver, in plowing furrows in the surface of the
            copper, raises corresponding ridges or burrs.
                                                  --Tomlinson.

   3. A thin flat piece of metal, formed from a sheet by
      punching; a small washer put on the end of a rivet before
      it is swaged down.

   4. A broad iron ring on a tilting lance just below the gripe,
      to prevent the hand from slipping.

   5. The lobe or lap of the ear.

   6. [Probably of imitative origin.] A guttural pronounciation
      of the letter r, produced by trilling the extremity of the
      soft palate against the back part of the tongue; rotacism;
      -- often called the Newcastle, Northumberland, or
      Tweedside, burr.

   7. The knot at the bottom of an antler. See {Bur}, n., 8.

Source : WordNet®

burr
     n 1: seed vessel having hooks or prickles [syn: {bur}]
     2: rough projection left on a workpiece after drilling or
        cutting
     3: United States politician who served as Vice President under
        Jefferson; he mortally wounded his political rival
        Alexander Hamilton in a duel and fled south (1756-1836)
        [syn: {Aaron Burr}]
     4: rotary file for smoothing rough edges left on a workpiece
     5: small bit used in dentistry or surgery [syn: {bur}]

burr
     v : remove the burrs from [syn: {bur}]