◙ noun 1. each of the pair of organs situated within the ribcage, consisting of elastic sacs with branching passages into which air is drawn, so that oxygen can pass into the blood and carbon dioxide be removed. Lungs are characteristic of avertebrates other than fish, though similar structures are present in some other animal groups • 肺 [一般作 lungs] (figurative)the open spaces in a town or city, where its inhabitants can get fresher air • [喻] （市内）空气新鲜的空旷地