DuckCorp Dico

Found one definition

1.                 From The Collaborative International Dictionary of English v.0.48:
                   
   
   
                   
                     
   Blatter \Blat"ter\, v. i. [imp. & p. p. Blattered.] [L.
      blaterare to babble: cf. F. blat['e]rer to bleat.]
      To prate; to babble; to rail; to make a senseless noise; to
      patter. [Archaic] "The rain blattered." --Jeffrey.
      [1913 Webster]
            They procured . . . preachers to blatter against me, .
            . . so that they had place and time to belie me
            shamefully.                              --Latimer.
      [1913 Webster]