swans·down \ˈswänzˌdau̇n also -wȯn-\noun Etymology:swan's (gen. of swan) (I) + down 1.: the soft downy feathers of the swan especially when used as trimming on articles of dress < she was wrapped in grey satin edged with swansdown — Victoria Sackville-West > 2.: a heavy cotton flannel with a thick nap on the face made with sateen weave