'retainer' originates from Old French, specifically the word 'retenir,' where 're-' meant 'again' and 'tenir' meant 'to hold.'

'retenir' transformed into the Middle English word 'retainen,' and eventually became the modern English word 'retainer.'

Initially, it meant 'to hold back or keep,' but over time it evolved into its current meanings of 'a device that holds something in place' and 'a servant or attendant.'