'apparel' originates from Old French, specifically the word 'appareil' / 'apareill', where the element 'a-' (from Latin ad-) meant 'to/toward' and 'parer' meant 'to prepare/make ready'.

'apparel' changed from Old French 'appareil'/'apareill' into Middle English forms such as 'apareill' or 'apparail', and eventually became the modern English word 'apparel'.

Initially it meant 'equipment, preparation' or 'that which makes ready', but over time the sense narrowed and shifted to refer specifically to 'clothing, dress'.