<p><strong>Noun</strong></p><ul><li>any of several tawny brown herons that inhabit reedy marshes, as <em>Botaurus lentiginosus</em> (American bittern) of North America, and <em>B. stellaris</em> of Europe.</li><li>any of several small herons of the genus <em>Ixobrychus</em>, as <em>I. exilis</em> (least bittern), of temperate and tropical North and South America.</li></ul>