'memory-retentive' originates from the combination of 'memory' and 'retentive', where 'memory' refers to the faculty by which the mind stores and remembers information, and 'retentive' means having the ability to remember facts and impressions easily.

'Memory-retentive' combines the Middle English word 'memorie' from Latin 'memoria' and the Middle English 'retentif' from Latin 'retentivus'.

Initially, it meant 'having the ability to retain information', and this meaning has largely remained the same in modern usage.