a. 1. Causing one to rue or lament; woeful; mournful; sorrowful. [ 1913 Webster ]
2. Expressing sorrow. “Rueful faces.” Dryden. [ 1913 Webster ]
Two rueful figures, with long black cloaks. Sir W. Scott. [ 1913 Webster ]
-- Rue"ful*ly, adv. -- Rue"ful*ness, n. [ 1913 Webster ]