Source : Webster's Revised Unabridged Dictionary (1913)

Bulk \Bulk\ (b[u^]lk), n. [OE. bulke, bolke, heap; cf. Dan. bulk
   lump, clod, OSw. bolk crowd, mass, Icel. b?lkast to be bulky.
   Cf. {Boll}, n., {Bile} a boil, {Bulge}, n.]
   1. Magnitude of material substance; dimensions; mass; size;
      as, an ox or ship of great bulk.

            Against these forces there were prepared near one
            hundred ships; not so great of bulk indeed, but of a
            more nimble motion, and more serviceable. --Bacon.

   2. The main mass or body; the largest or principal portion;
      the majority; as, the bulk of a debt.

            The bulk of the people must labor, Burke told them,
            ``to obtain what by labor can be obtained.'' --J.
                                                  Morley.

   3. (Naut.) The cargo of a vessel when stowed.

   4. The body. [Obs.] --Shak.

            My liver leaped within my bulk.       --Turbervile.

   {Barrel bulk}. See under {Barrel}.

   {To break bulk} (Naut.), to begin to unload or more the
      cargo.

   {In bulk}, in a mass; loose; not inclosed in separate
      packages or divided into separate parts; in such shape
      that any desired quantity may be taken or sold.

   {Laden in bulk}, {Stowed in bulk}, having the cargo loose in
      the hold or not inclosed in boxes, bales, or casks.

   {Sale by bulk}, a sale of goods as they are, without weight
      or measure.

   Syn: Size; magnitude; dimension; volume; bigness; largeness;
        massiveness.

Bulk \Bulk\, v. i. [imp. & p. p. {Bulked}; p. pr. & vb. n.
   {Bulking}.]
   To appear or seem to be, as to bulk or extent; to swell.

         The fame of Warburton possibly bulked larger for the
         moment.                                  --Leslie
                                                  Stephen.

Bulk \Bulk\, n. [Icel. b[=a]lkr a beam, partition. Cf. {Balk},
   n. & v.]
   A projecting part of a building. [Obs.]

         Here, stand behind this bulk.            --Shak.

Source : WordNet®

bulk
     n 1: the property resulting from being or relating to the greater
          in number of two parts; the main part; "the majority of
          his customers prefer it"; "the bulk of the work is
          finished" [syn: {majority}] [ant: {minority}]
     2: the property of something that is great in magnitude; "it is
        cheaper to buy it in bulk"; "he received a mass of
        correspondence"; "the volume of exports" [syn: {mass}, {volume}]
     3: the property possessed by a large mass
     v 1: stick out or up; "The parcel bulked in the sack"
     2: cause to bulge or swell outwards [syn: {bulge}]