<p><strong>Noun</strong></p><ul><li>Anatomy, Zoology.<ul><li>the basinlike cavity in the lower part of the trunk of many vertebrates, formed in humans by the innominate bones, sacrum, etc.</li><li>the bones forming this cavity.</li><li>the cavity of the kidney that receives the urine before it is passed into the ureter.</li></ul></li></ul>