DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   formation
       n 1: an arrangement of people or things acting as a unit; "a
            defensive formation"; "a formation of planes"
       2: the act of fabricating something in a particular shape [syn:
          formation, shaping]
       3: the act of forming or establishing something; "the
          constitution of a PTA group last year"; "it was the
          establishment of his reputation"; "he still remembers the
          organization of the club" [syn: constitution,
          establishment, formation, organization, organisation]
       4: (geology) the geological features of the earth [syn:
          geological formation, formation]
       5: a particular spatial arrangement
       6: natural process that causes something to form; "the formation
          of gas in the intestine"; "the formation of crystals"; "the
          formation of pseudopods"
       7: creation by mental activity; "the formation of sentences";
          "the formation of memories"