'apeptic' originates from Greek, specifically the word 'apeptikos', where 'a-' meant 'not' and 'peptikos' meant 'relating to digestion.'

'apeptic' entered English via New Latin (for example 'apepticus') in scientific and medical texts, and eventually became the English adjective 'apeptic'.

Initially it meant 'not digestible' or 'preventing digestion', and this sense has been retained in specialized medical usage.