Source : Webster's Revised Unabridged Dictionary (1913)

Smutty \Smut"ty\, a. [Compar. {Smuttier}; superl. {Smuttiest}.]
   1. Soiled with smut; smutted.

   2. Tainted with mildew; as, smutty corn.

   3. Obscene; not modest or pure; as, a smutty saying.

            The smutty joke, ridiculously lewd.   --Smollett.
      -- {Smut"ti*ly}, adv. -- {Smut"ti*ness}, n.

Source : WordNet®

smutty
     adj : characterized by obscenity; "had a filthy mouth"; "foul
           language"; "smutty jokes" [syn: {filthy}, {foul}, {nasty}]