flue

The story

1. Middle English · derived fromfloute
2. Old English · derived fromflēwsa“a flow, flowing, flux”
3. Middle English · derived from*flews
4. Middle English · inherited fromflue
5. English todayflue

From Middle English flue, flewe (“mouthpiece of a hunting horn”), of uncertain origin. Perhaps a back-formation from Middle English *flews (mistaken as a plural), from Old English flēwsa (“a flow, flowing, flux”). Alternatively, perhaps an alteration of Middle English floute, fleute, flote (“a pipe”), see English flute. Compare also Middle Dutch vloegh (“groove, channel, flute of a fluted column”).