'coif' originates from Old French, specifically the word 'coiffe', where 'coiffe' meant 'a hood or cap' worn on the head.

'coiffe' changed into Middle English as 'coif' (meaning a close-fitting cap). The verb senses (from Old French 'coiffer' meaning 'to put a cap on, to dress the hair') developed and yielded the English verb 'to coif' and forms such as 'coiffed'.

Initially, it meant 'a cap or hood', but over time it evolved into its current sense related to hair: 'a hairstyle' or 'to arrange/style hair'.