Solitudinous is a unique and sophisticated word, which refers to being solitary or secluded. However, there are many synonyms of this word, which carry the same meaning but with different nuances. Isolated, lone, and solitary are all synonyms that describe the feeling of being alone. However, they do not carry the same sense of seclusion as what solitudinous incites. Secluded, reclusive, and withdrawn would better describe the seclusion aspect of being solitudinous. Another synonym is introverted, which suggests a preference to being alone instead of socializing. Ultimately, the synonyms for the word solitudinous vary in their depth and subtlety, but they all evoke the sense of being alone in one way or another.