'aporrhoea' originates from Greek, specifically the word 'aporrhoia', where 'apo-' meant 'away' and 'rhein' meant 'to flow'.

'aporrhoea' passed into scientific and medical Latin (as 'aporrhoea') and then into English usage via Late/Medieval Latin and medical terminology.

Initially, it meant 'a flowing away', but over time it evolved into its current medical sense of 'a discharge or efflux'.