phlegm

From Middle English flewme, fleume, fleme, from Old French fleume, Middle French flemme (French flegme), and their source, Latin phlegma, from Ancient Greek φλέγμα (phlégma, “flame; inflammation; clammy humor in the body”), from φλέγειν (phlégein, “to burn”). Possible burning sensation when coughing up phlegm. Compare phlox, flagrant, flame, bleak (adjective), fulminate. Spelling later altered to resemble the word's Latin and Greek roots. The regularly developed form /fliːm/ has been displaced by a pronunciation /flɛm/ of uncertain provenance. It may be inherited, though some kind of learned or spelling pronunciation or influence from phlegmatic is also conceivable.