'armlet' originates from English, formed by combining the noun 'arm' (from Old English 'earm') with the diminutive suffix '-let' (from Old French '-let'), where '-let' meant 'small'.

'arm' developed from the Old English word 'earm' into Middle English 'arm'; the diminutive suffix '-let' came via Old French '-let'; these elements combined in English to form 'armlet' (literally 'little arm [band]').

Initially it conveyed the idea of a 'small thing for the arm' (a small covering or ornament); over time it became specialized to mean specifically 'a band or ornamental bracelet worn around the upper arm.'