'bandeau' originates from French, specifically the word 'bandeau,' where 'bande' meant 'band' and the suffix '-eau' formed a diminutive/derivative (a little band).

'bandeau' was borrowed into English from French (bandeau). The French word comes from Old French 'bande' (band), ultimately related to a Germanic root (Frankish *banda) meaning 'strip' or 'band', and over time the French form entered English retaining the sense of a band for head or chest.

Initially it meant 'a band or headband' in French and early English usage, but over time it also came to denote a strapless chest garment (a simple tube or bra-like top).