The Collaborative International Dictionary of English v.0.48:

Slang \Slang\, v. t. [imp. & p. p. Slanged; p. pr. & vb. n.
   Slanging.]
   To address with slang or ribaldry; to insult with vulgar
   language. [Colloq.]
   [1913 Webster]

         Every gentleman abused by a cabman or slanged by a
         bargee was bound there and then to take off his coat
         and challenge him to fisticuffs.         --London
                                                  Spectator.
   [1913 Webster]