'buy' originates from Old English, specifically the word 'bycgan' (also attested as 'bugan'), where the Proto-Germanic root *bugjan is the likely source meaning 'to buy, to use in exchange'.

'buy' changed from Old English 'bycgan' to Middle English forms such as 'buyen' and eventually became the modern English word 'buy'.

Initially it meant 'to obtain by exchange or purchase', and this basic meaning has largely remained the same into modern usage.