noun
flat cap; hunting cap
A soft, round cap with a small stiff brim in front, often made of tweed or similar fabric. Commonly worn in casual or vintage styles.
祖父はよくハンチング帽をかぶって散歩に出かける。
My grandfather often goes for a walk wearing a flat cap.
キャスケット is a similar flat cap, but often refers to a newsboy cap with a fuller, rounder shape and a button on top, while ハンチング帽 typically has a more streamlined, single-panel design.
From English 'hunting cap', with ハンチング as a wasei-eigo shortening of 'hunting', combined with 帽 (ぼう, 'cap').