<p><strong>Verb (used with object)</strong></p><ul><li>to double; make twice as great: If you hope to win that client, you'll have to redouble your efforts to impress her.</li><li>to echo or reecho.</li><li>Bridge. to double the double of (an opponent).</li><li>to go back over: I redoubled my footsteps, trying to find my lost earring.</li><li>Archaic. to repeat.</li></ul><p><strong>Verb (used without object)</strong></p><ul><li>to be doubled; become twice as great.</li><li>to be echoed; resound.</li><li>Bridge. to double the double of an opponent.</li></ul><p><strong>Noun</strong></p><ul><li>Bridge. the act of doubling one's opponent's double.</li><li>Fencing. an attack in a line other than that of the previous attack, made after the failure of the opponent to follow their parry of the previous attack with a riposte.</li></ul>