<p><strong>Noun:</strong></p><ul><li>Any rigid structural member projecting from a vertical support, especially one in which the projection is great in relation to the depth, so that the upper part is in tension and the lower part in compression.</li><li>Any rigid construction extending horizontally well beyond its vertical support, used as a structural element of a bridge, building foundation, etc.</li><li>A form of wing construction in aeronautics in which no external bracing is used.</li><li>A bracket for supporting a balcony, cornice, etc.</li></ul><p><strong>Verb (used without object):</strong></p><ul><li>To project in the manner of a cantilever.</li></ul><p><strong>Verb (used with object):</strong></p><ul><li>To construct in the manner of a cantilever.</li></ul>