'apophlegm' originates from Greek, specifically the word 'apophlegma,' where 'apo-' meant 'away' and 'phlegma' meant 'inflammation, phlegm'.

'apophlegm' entered classical and medieval medical Latin from Greek 'apophlegma' and was recorded in Late Latin/Medieval English medical or antiquarian texts before becoming rare/archaic in modern English.

Initially, it meant 'that which is cast off (away) as phlegm' or 'the act of expelling phlegm'; over time it remained close to this medical/physical sense but fell out of general usage and became archaic.