'arbitrageur' originates from French, specifically the word 'arbitrageur', where the root relates to 'arbiter' meaning 'judge' or 'one who decides'.

'arbitrageur' changed from French financial usage 'arbitrage' (settlement or decision) and the agent-form '-eur' into English financial jargon, becoming 'arbitrageur' to mean someone who performs arbitrage.

Initially related to judging or settling disputes (from 'arbiter'), it evolved in financial contexts to mean 'one who takes advantage of price differences', the current primary meaning.