'arbitrageur' originates from French, specifically the word 'arbitrageur', where 'arbitrage' (from French 'arbiter' < Latin 'arbiter') meant 'judgment' or 'settlement' (i.e., decision by an arbitrator).

'arbitrageur' changed from the French word 'arbitrageur' and was borrowed into English in the 19th century; over time the term became specialised in finance to denote someone who profits from price differences between markets.

Initially, it meant 'one who arbitrates or settles disputes', but over time it evolved into its current meaning of 'a person who takes advantage of price differences between markets to make a profit'.