A flat cap is a rounded cap with a small stiff brim in front. The hat is also known as a cabbie cap, gatsby cap, longshoremans cap, cloth cap, scally cap, Wigens cap, ivy cap, derby hat, jeff cap, duffer cap, duckbill cap, driving cap, bicycle cap, Irish cap, newsboy cap, crook cap, Vergon hat, Joaos hat, sixpence, or a paddy cap, and in regional varieties: in Scotland as a bunnet, in Wales as a Dai cap, and in New Zealand, as a cheese-cutter.
Cloths used to make the cap include wool, tweed (most common), and cotton. Less common materials may include leather, linen, or corduroy. The inside of the cap is commonly lined for comfort and warmth.