a cap made of soft cloth with no brim or bill, widening somewhat outward from a close-fitting headband to a flat top, which often has a button or tab in its center.
A round flat woollen cap, usually of military style..
Round soft hat often made from felt, but can be knitted. Popular during the first and second world wars and is still a item of military uniform today. It’s most noted revival was in the late 1960s and 1970s. examples