bonet

Old French bonet (later bonnet) meant a cap or hat worn by men. The word may come from Medieval Latin abonnis, a type of cap, but the deeper origin is unclear. In fourteenth-century England, a bonnet was a man's soft, brimless cap. Knights wore bonnets under their helmets. Scottish men wore blue bonnets as a symbol of national identity. The word was masculine for most of its history.

The shift to women's headwear happened in the eighteenth century. As men's hats stiffened into structured forms — tricornes, top hats, bowlers — the soft bonnet migrated to women's fashion. By the nineteenth century, a bonnet was specifically a woman's hat that framed the face and tied under the chin. Jane Austen's characters wear bonnets. The prairie bonnet protected settlers from sun. The poke bonnet, with its projecting brim, defined Regency and Victorian feminine fashion.

British English extended bonnet to the covering over a car's engine — what Americans call the hood. The metaphor was straightforward: a bonnet covered and protected what was beneath it, whether a head or an engine block. The usage dates to the early days of motoring in the 1900s. The American hood and the British bonnet name the same object with different metaphors — one from headwear, the other from a monk's cowl.

The bonnet as headwear has largely disappeared from daily life. War bonnets, sun bonnets, baby bonnets — these survive in specific contexts but not in mainstream fashion. The word lives most actively in British automotive vocabulary and in historical costume. A word that spent centuries on men's heads, moved to women's heads, and ended up on cars.