The pāo reading is much rarer than pào (this is the alternate reading). It describes a light, hollow, puffed-up quality — air-filled rather than dense. Found in
泡桐 (Paulownia, a tree with light spongy wood),
眼泡 (puffy upper eyelid), and in the northeastern dialect compound
尿泡 (bladder). In place names of Jilin and Heilongjiang,
泡 can also mean a small lake.