swansdown
/ˈsweɪnzdaʊn/Definitions
1. noun
the soft, fluffy down from a swan, used in making dress materials or as a filling
“The designer used swansdown to create the luxurious winter coat.”
2. noun
a type of high-quality down bedding or duvet
“The hotel room came with a luxurious swansdown duvet and crisp white sheets.”