'episodic' originates from Greek, specifically the word 'epeisodios' (from 'epeisodion'), where 'epi-' meant 'upon, in addition' and 'hodos' (via the element in 'epeisodion') meant 'way' or 'journey'.

'episodic' changed from the Greek word 'epeisodios' through Late Latin/French forms (e.g. Medieval Latin/Latinized 'episodicus', French 'épisodique') and eventually became the modern English word 'episodic'.

Initially, it meant 'relating to an occurrence or incident (an episode)'; over time it came to be used more broadly for things that occur in separate or disconnected events and, in psychology, to describe memories of specific events ('episodic memory').