'memory-enhancing' is a compound formed in modern English from 'memory' + 'enhancing'. 'Memory' comes from Latin 'memoria' (via Old French 'memoire') meaning 'remembrance', and 'enhancing' is the present-participle form of 'enhance', which comes from Old French 'enhauncer' (from Vulgar Latin inaltiare) where elements relate to Latin 'altus' meaning 'high'.

'memory' developed from Latin 'memoria' → Old French 'memoire' → Middle English 'memory'. 'Enhance' passed from Old French 'enhauncer' into Middle English and later became the modern English 'enhance'; adding '-ing' produced 'enhancing', and the two elements were combined into the compound adjective 'memory-enhancing'.

Individually, 'memory' originally meant 'remembrance' and 'enhance' meant 'to raise or increase'; together as the compound they took on the specific modern sense 'serving to improve remembrance or recall'.