'psychological-continuity' is a compound of 'psychological' and 'continuity'. 'Psychological' ultimately originates from Greek 'psychē' (ψυχή) via Latin/Modern Latin and French, where 'psychē' meant 'soul, mind'. 'Continuity' originates from Latin 'continuitas', from 'continere' (con- + tenere), where 'tenere' meant 'to hold, keep together', and came into English via Old French and Middle English.

'psychological' developed from Greek 'psychē' → Late Latin/Medieval Latin 'psychologia' → French/English 'psychology' and adjective 'psychological'; 'continuity' changed from Latin 'continuitas' → Old French 'continuité' → Middle English 'continuite' and became modern English 'continuity'. The compound 'psychological continuity' arose in modern philosophical writing (20th century) to name the concept linking mind-related features across time.

Individually, 'psychological' originally referred to matters of the soul/mind and has come to mean 'relating to the mind or mental processes'; 'continuity' originally meant 'the state of being continuous or unbroken' and retains that core sense. Combined as 'psychological-continuity', the phrase specialized in philosophy to mean 'mind-based persistence of identity' in the 20th century.