Source : Webster's Revised Unabridged Dictionary (1913)

Group \Group\, v. t. [imp. & p. p. {Grouped}; p. pr. & vb. n.
   {Grouping}.] [Cf. F. grouper. See {Group}, n.]
   To form a group of; to arrange or combine in a group or in
   groups, often with reference to mutual relation and the best
   effect; to form an assemblage of.

         The difficulty lies in drawing and disposing, or, as
         the painters term it, in grouping such a multitude of
         different objects.                       --Prior.

   {Grouped columns} (Arch.), three or more columns placed upon
      the same pedestal.

Grouping \Group"ing\, n. (Fine Arts)
   The disposal or relative arrangement of figures or objects,
   as in, drawing, painting, and sculpture, or in ornamental
   design.

Source : WordNet®

grouping
     n 1: any number of entities (members) considered as a unit [syn:
          {group}]
     2: the activity of putting things together in groups
     3: a system for classifying things into groups [syn: {pigeonholing}]