Synonyms for Contrite (same or very similar meaning)
WordNet sense 1 (feeling or expressing pain or sorrow for sins or offenses):
remorseful, rueful, ruthfulWordNet sense 2 (feeling or expressing remorse for misdeeds):
penitent, repentantWordNet sense 3 (offering or expressing apology):
apologetic, excusatoryFrom the ODE community, based on WordNetadd/edit