Twi-bille

According to the Old English Dictionary:

twi-bille

adj. Double-edged :-- Bipennis twibille vel stānæx (the double gloss seems to render the double character of the Latin word as adjective and noun; a little later (see preceding word) in the same glossary bipennis as noun is rendered by twybill), Wrt. Voc. i. 34, 60. twi-bille