<p><strong>Adjective</strong></p><ul><li>completely engrossed in thought; absorbed.</li></ul><p><strong>Synonyms</strong></p><ul><li>busy</li><li>previously occupied</li><li>taken</li><li>filled</li></ul><p><strong>Biology</strong></p><ul><li>already used as a name for some species, genus, etc., and not available as a designation for any other.</li></ul>