Bonnet
late Middle English (denoting a soft brimless hat for men): from Old French bonet, from medieval Latin abonnis ‘headgear’. bonnet (sense 1) dates from the late 15th century.
wiktionary
From Middle English bonet, from Middle French bonet (Modern French bonnet), from Old French bonet(“material from which hats are made”), from Frankish *bunni(“that which is bound”), from Proto-Germanic *bundiją(“bundle”), from Proto-Indo-European *bʰendʰ-(“to tie”). Compare also Late Latin abbonis, obbonis(“ribbon of a headdress”), also of Germanic origin, from Frankish *obbunni, from *ob-(“above, over”) + *bunni. Cognate with Old High German gibunt(“band, ribbon”), Middle Dutch bont(“bundle, truss”), Gothic 𐌲𐌰𐌱𐌿𐌽𐌳𐌹( gabundi, “bond”). More at over, bundle.
etymonline
bonnet (n.)
early 15c., "kind of cap or bonnet worn by men and women," from Old French bonet, short for chapel de bonet, from bonet (12c., Modern French bonnet) "kind of cloth used as a headdress," from Medieval Latin bonitum, bonetum "material for hats," perhaps a shortening of Late Latin abonnis "a kind of cap" (7c.), which is perhaps from a Germanic source.
As a form of head-covering worn by women out-of-doors, late 15c. As a type of mechanical covering device, 1862.
