This one is courtesy the dictionary.com 'word of the day' feed on my Novell (formerly Ximian) Evolution summary page:
ribald, adj. -- derived from the Old French ribaud, from riber, "to be wanton," from Old High German riban, "to be amorous" (originally, "to rub"); uh, I see where this is going, and I won't continue down that road ...
Anyway -- meaning: "characterized by or given to vulgar humor; coarse."
Thank you dictionary.com.