Noun
A kind of low-crowned cap formerly worn by all classes in England, and continued in London after disuse elsewhere; -- hence, a citizen of London.
Source: Webster's dictionaryflat cap
Even with the coronavirus-induced flat cap, it’s reasonable to expect there’s a team that will go at least that high in salary and then tack on the seventh season. Source: Internet
Magnotta appeared wearing a flat cap, leather jacket and tracksuit bottoms. Source: Internet