Source : Webster's Revised Unabridged Dictionary (1913)

Lump \Lump\, n. [Cf. OD. lompe piece, mass. Cf. {Lunch}.]
   1. A small mass of matter of irregular shape; an irregular or
      shapeless mass; as, a lump of coal; a lump of iron ore. ``
      A lump of cheese.'' --Piers Plowman. `` This lump of
      clay.'' --Shak.

   2. A mass or aggregation of things.

   3. (Firearms) A projection beneath the breech end of a gun
      barrel.

   {In the lump},

   {In a lump}, the whole together; in gross.

            They may buy them in the lump.        --Addison.

   {Lump coal}, coal in large lumps; -- the largest size brought
      from the mine.

   {Lump sum}, a gross sum without a specification of items; as,
      to award a lump sum in satisfaction of all claims and
      damages.