'auction' originates from Latin, specifically the word 'auctio', where the root 'auct-' (from 'augere') meant 'to increase' (in the sense of an increase or act of selling by bidding).

'auction' changed from Middle English 'auctioun' (borrowed via Old French) and ultimately derives from Latin 'auctio'; over time the term came to refer specifically to a public sale to the highest bidder and became the modern English word 'auction'.

Initially it related to 'increase' or 'sale by public proclamation', but over time it evolved into the narrower modern meaning 'a public sale to the highest bidder'.