'memory-impairing' is a compound of 'memory' and 'impairing'. 'memory' originates from Latin, specifically the word 'memoria', where 'memor' meant 'mindful' or 'remembering'. 'impair' originates from Old French, specifically 'empeirier' (from roots related to making worse), ultimately tracing to Latin 'peior' meaning 'worse'. 'impairing' is the present participle form of 'impair'.

'memory' entered English via Old French 'memorie' and Middle English 'memorye', eventually becoming modern English 'memory'. 'impair' developed from Old French 'empeirier' into Middle English forms such as 'empairen' and then modern English 'impair'; the participle 'impairing' and compounds like 'memory-impairing' followed from these forms.

Individually, 'memory' originally meant 'the faculty or act of remembering' and 'impair' meant 'to make worse'; together as 'memory-impairing' the compound has come to mean 'causing deterioration of memory function'.