'apophthegm' originates from Greek, specifically the word 'apophthēgma', where 'apo-' meant 'away' and the root related to 'phthengesthai' meant 'to utter/declare'.

'apophthēgma' passed into Late Latin as 'apophthegma' and then into Middle English (via Medieval Latin/Old French spellings) as forms such as 'apophtegme' before becoming the modern English 'apophthegm'.

Initially it referred to an utterance or spoken saying ('something spoken out'); over time the meaning narrowed to the modern sense of a concise, pithy saying or maxim.