The word "ruefulnesses" is quite uncommon. It means the state of feeling regretful or sorrowful. As such, some synonyms for it include remorse, regret, sorrow, contrition, penitence, guilt, shame, sadness, and disappointment. Each of these words represents a slightly different emotion associated with feelings of regret or sorrow. For instance, remorse connotes deep regret and self-reproach, while penitence implies a willingness to make amends for one's mistakes. Synonyms for "ruefulnesses" can help add variety and depth to writing, allowing for a more nuanced and precise expression of emotions.