foulmouthed

from The Collaborative International Dictionary of English v.0.48

Foul-mouthed \Foul"-mouthed`\, a.
   Using language scurrilous, opprobrious, obscene, or profane;
   abusive; as, noisy foul-mouthed women all shouting at once.

   Syn: foul-spoken.
        [1913 Webster + WordNet 1.5]

              So foul-mouthed a witness never appeared in any
              cause.                              --Addison.
        [1913 Webster]