<p><strong>Noun</strong></p><ul><li>a fortified, usually walled residence, as of a prince or noble in feudal times.</li><li>the chief and strongest part of the fortifications of a medieval city.</li><li>a strongly fortified, permanently garrisoned stronghold.</li><li>a large and stately residence, especially one with high walls and towers, that imitates the form of a medieval castle.</li><li>any place providing security and privacy: It may be small, but my home is my castle.</li><li>Chess: the rook.</li></ul><p><strong>Synonyms</strong></p><ul><li>citadel</li><li>fortress</li><li>château</li><li>palace</li></ul>