Obs. [cf. ‘Exmoor bourn yeast’ (Halliw.).] ‘Wort, or boiled liquor.’ (Fuller.)
1609. C. Butler, Fem. Mon., x. The end of boiling is thoroughly to incorporate the Boorne and the Honie.
1662. Fuller, Worthies, IV. 6. [in a receipt for metheglin] Take … one Gallon of the finest Honey, and put it into the Boorn.
