kapok
/ˈkeɪpɑk/
noun
- A soft, fluffy fiber from the seeds of the kapok tree, used for stuffing pillows, life jackets, and insulation.
- She bought a pillow stuffed with kapok because it was lightweight and comfortable.
- The life jacket was filled with kapok to keep it buoyant.
- Kapok is often used in sleeping bags for its insulating properties.