'retentiveness' originates from Latin, specifically the word 'retentivus,' where 're-' meant 'again' and 'tenere' meant 'to hold.'

'retentivus' transformed into the Old French word 'retentif,' and eventually became the modern English word 'retentive' through Middle English.

Initially, it meant 'capable of holding or keeping,' and over time it evolved into its current meaning of 'the ability to remember or retain information.'