'instep' originates from Old English, formed from the preposition 'in' + the word 'stepp' (or 'stæpp'), where 'in' meant 'in/on' and 'stepp' meant 'step' or 'foot'.

'instep' changed from the Middle English form 'instep(e)' (from Old English components) and eventually became the modern English word 'instep'.

Initially, it referred to the area of the foot associated with a 'step' (the upper/inner part of the foot), and over time it has retained that core meaning, later also referring to the corresponding part of footwear.