(a) A tube or hollow cylinder employed as a receptacle or passage for liquid, smoke, etc.; the nozzle of a bellows; flue of a chimney; beli pipe, the nozzle of a bellows; (b) a water pipe, conduit……

(a) A natural or man-made depression in the ground, hole, pit, ditch; cave; also fig.; also, an open excavation from which some mineral product is obtained or in which some industrial process is……