From Longman Dictionary of Contemporary Englishflat capˌflat ˈcap noun [countable] British English DCCa cap made of cloth, with a stiff piece that sticks out at the front
Examples from the Corpus
flat cap• He was holding a flat cap full of coins.• Glancing towards the car park, I am transfixed by the sight of a man in a flat cap cleaning our car.• He was wearing a flat cap, a suit and a choker, and there were dock gates in the background.• Newley was wearing a flat cap made of tweed.• An elderly man in flat cap and going-out clothes was leaning against the fence, stick hanging from a crooked elbow.• But you wouldn't expect him to turn up wearing an Albert Tatlock-style flat cap! 