'retention' originates from Latin, specifically the word 'retentio' (from 'retinere'), where 're-' meant 'back' and 'tenere' (or 'tinere') meant 'to hold'.

'retention' changed from Old French 'retencion' and Middle English 'retencioun' and eventually became the modern English word 'retention'.

Initially, it meant 'the act of holding back or keeping', and over time it expanded to include 'the act of keeping or preserving', 'amounts withheld', and 'the ability to remember'.