Source : Webster's Revised Unabridged Dictionary (1913)

Level \Lev"el\, v. t. [imp. & p. p. {Leveled} (-[e^]ld) or
   {Levelled}; p. pr. & vb. n. {Leveling} or {Levelling}.]
   1. To make level; to make horizontal; to bring to the
      condition of a level line or surface; hence, to make flat
      or even; as, to level a road, a walk, or a garden.

   2. To bring to a lower level; to overthrow; to topple down;
      to reduce to a flat surface; to lower.

            And their proud structures level with the ground.
                                                  --Sandys.

            He levels mountains and he raises plains. --Dryden.

   3. To bring to a horizontal position, as a gun; hence, to
      point in taking aim; to aim; to direct.

            Bertram de Gordon, standing on the castle wall,
            leveled a quarrel out of a crossbow.  --Stow.

   4. Figuratively, to bring to a common level or plane, in
      respect of rank, condition, character, privilege, etc.;
      as, to level all the ranks and conditions of men.

   5. To adjust or adapt to a certain level; as, to level
      remarks to the capacity of children.

            For all his mind on honor fixed is, To which he
            levels all his purposes.              --Spenser.

Leveling \Lev"el*ing\, n. [Written also levelling.]
   1. The act or operation of making level.

   2. (Surveying) The art or operation of using a leveling
      instrument for finding a horizontal line, for ascertaining
      the differences of level between different points of the
      earth's surface included in a survey, for establishing
      grades, etc., as in finding the descent of a river, or
      locating a line of railroad.

   {Leveling instrument}. See {Surveyor's level}, under {Level},
      n.

   {Leveling staff}, a graduated rod or staff used in connection
      with a leveling instrument for measuring differences of
      level between points.

Source : WordNet®

leveling
     n 1: changing the ground level to a smooth horizontal or gently
          sloping surface [syn: {grading}]
     2: complete destruction of a building [syn: {razing}, {tearing
        down}, {demolishing}]
     3: the act of making equal or uniform [syn: {equalization}, {equalisation}]