kapok

noun3

1. •
   A silky fibre obtained from seed pods of the silk-cotton tree (Ceiba pentandra) used for insulation and stuffing for mattresses, pillows, etc.

   • You can stuff them full of kapok to make a decent cushion and there is nothing better to carry frogs in. — 1985
2. •
   A silk-cotton tree (Ceiba pentandra).
3. •
   A cotton tree, Malabar silk-cotton tree, or red silk-cotton tree (Bombax ceiba).