Source : Webster's Revised Unabridged Dictionary (1913)

Ribald \Rib"ald\, a.
   Low; base; mean; filthy; obscene.

         The busy day, Waked by the lark, hath roused the ribald
         crows.                                   --Shak.

Ribald \Rib"ald\, n./ [OE. ribald, ribaud, F. ribaud, OF.
   ribald, ribault, LL. ribaldus, of German origin; cf. OHG
   hr[=i]pa prostitute. For the ending -ald cf. E. {Herald}.]
   A low, vulgar, brutal, foul-mouthed wretch; a lewd fellow.
   --Spenser. Pope.

         Ribald was almost a class name in the feudal system . .
         . He was his patron's parasite, bulldog, and tool . . .
         It is not to be wondered at that the word rapidly
         became a synonym for everything ruffianly and brutal.
                                                  --Earle.

Source : WordNet®

ribald
     adj : humorously vulgar; "bawdy songs"; "off-color jokes"; "ribald
           language" [syn: {bawdy}, {off-color}]
     n : a ribald person; someone who uses vulgar and offensive
         language