cadie, caidy, chaydy, kaidie, kaidi noun a peaked cap; a bonnet 20-. etymology: Scots; Romany attests a form kaydi; originally the military cap of the Scottish Highland Regiments so perhaps connected with cadet; forms caidy and kaidie attested by Galloway and Perthshire and Argyleshire Tinkler Gypsies and BS in TDITA; also collected by EMcC/PS; forms chaydy, kaidi attested in Shelta note:

Canadian Paul Pope (2013) cites the form kaidie a bonner’.