[key-pok] 
| the silky down that invests the seeds of a silk-cotton tree (kapok tree), Ceiba pentandra, of the East Indies, Africa, and tropical America: used for stuffing pillows, life jackets, etc., and for acoustical insulation. |
| ka·pok (kā'pŏk') n. A silky fiber obtained from the fruit of the silk-cotton tree and used for insulation and as padding in pillows, mattresses, and life preservers. [Malay kapuk.] |