Source : Webster's Revised Unabridged Dictionary (1913)

Wailful \Wail"ful\, a.
   Sorrowful; mournful. `` Like wailful widows.'' --Spenser.
   ``Wailful sonnets.'' --Shak.

Source : WordNet®

wailful
     adj : vocally expressing grief or sorrow or resembling such
           expression; "lamenting sinners"; "wailing mourners";
           "the wailing wind"; "wailful bagpipes"; "tangle her
           desires with wailful sonnets"- Shakespeare [syn: {lamenting},
            {wailing}]