<p><strong>Noun</strong></p><ul><li>A passage or duct for smoke in a chimney</li><li>Any duct or passage for air, gas, or the like</li><li>A tube, especially a large one, in a fire-tube boiler</li><li>Music: flue pipe</li><li>Also called windway</li><li>A narrow slit in the upper end of an organ pipe through which the air current is directed</li></ul>