The Collaborative International Dictionary of English v.0.48:

Bur \Bur\, Burr \Burr\ (b[^u]r), 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; a seed vessel
      having hooks or prickles. Also, any weed which bears burs.
      [1913 Webster]

            Amongst rude burs and thistles.       --Milton.
      [1913 Webster]

            Bur and brake and brier.              --Tennyson.
      [1913 Webster]

   2. The thin ridge left by a tool in cutting or shaping metal.
      See Burr, n., 2.
      [1913 Webster]

   3. A ring of iron on a lance or spear. See Burr, n., 4.
      [1913 Webster]

   4. The lobe of the ear. See Burr, n., 5.
      [1913 Webster]

   5. The sweetbread.
      [1913 Webster]

   6. A clinker; a partially vitrified brick.
      [1913 Webster]

   7. (Mech.)
      (a) A small circular saw.
      (b) A triangular chisel.
      (c) A drill with a serrated head larger than the shank; --
          especially a small drill bit used by dentists.
          [1913 Webster]

   8. [Cf. Gael. borr, borra, a knob, bunch.] (Zool.) The round
      knob of an antler next to a deer's head. [Commonly written
      burr.]
      [1913 Webster]

   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.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Burr \Burr\ (b[^u]r), n. [See Bur.] (Bot.)
   1. A prickly seed vessel. See Bur, 1.
      [1913 Webster]

   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.
      [1913 Webster]

            The graver, in plowing furrows in the surface of the
            copper, raises corresponding ridges or burrs.
                                                  --Tomlinson.
      [1913 Webster]

   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.
      [1913 Webster]

   4. A broad iron ring on a tilting lance just below the gripe,
      to prevent the hand from slipping.
      [1913 Webster]

   5. The lobe or lap of the ear.
      [1913 Webster]

   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 burr, Northumberland
      burr, or Tweedside burr.
      [1913 Webster]

   7. The knot at the bottom of an antler. See Bur, n., 8.
      [1913 Webster]

WordNet (r) 3.0 (2006):

burr
    n 1: seed vessel having hooks or prickles [syn: bur, burr]
    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: Burr,
       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 1: remove the burrs from [syn: bur, burr]

Moby Thesaurus II by Grady Ward, 1.0:

118 Moby Thesaurus words for "burr":
   accent, adherent, adhesive, barnacle, belch, blare, blat, boll,
   bramble, bray, brier, bristle, broad accent, brogue, bulldog, buzz,
   cackle, cactus, capsule, catchweed, caw, cement, chirr, chiseling,
   clang, clangor, clank, clash, cleavers, cod, craunch, croak,
   cross-hatching, crump, crunch, decal, decalcomania, demitint,
   drawl, engravement, engraving, etch, etching, follicle,
   gem-engraving, glass-cutting, glue, glyptic, goose grass, graving,
   grind, groan, growl, grumble, gunk, half tint, hatching, hull,
   husk, incision, inscript, inscription, jangle, jar, leech, legume,
   legumen, limpet, line, lining, marking, molasses, mucilage, needle,
   nettle, paste, pease cod, pericarp, pine needle, plaster, pod,
   prickle, quill, rasp, regional accent, remora, score, scoring,
   scranch, scrape, scratch, scratching, scrunch, seed pod,
   seed vessel, seedbox, seedcase, silique, slash, slashing, snarl,
   snore, spicule, spiculum, spike, spikelet, spine, sticker, stipple,
   stippling, syrup, thistle, thorn, tint, tooling, twang,
   type-cutting, yucca



U.S. Gazetteer Places (2000):

Burr, NE -- U.S. village in Nebraska
   Population (2000):    66
   Housing Units (2000): 40
   Land area (2000):     0.084109 sq. miles (0.217841 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.084109 sq. miles (0.217841 sq. km)
   FIPS code:            07205
   Located within:       Nebraska (NE), FIPS 31
   Location:             40.536891 N, 96.300651 W
   ZIP Codes (1990):     68324
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Burr, NE
    Burr