boiled wool
knitted or woven wool fabric that has been heavily fulled and shrunk to a dense, felt-like textile that is warm, lightweight, and windproof
en-US/ˈbɔɪld ˈwʊl/
en-GB/ˈbɔɪld ˈwʊl/
knitted or woven wool fabric that has been heavily fulled and shrunk to a dense, felt-like textile that is warm, lightweight, and windproof