The story
- Medieval Latin · derived from*batāre“to gape, yawn, be open”
- Old French · derived frombaïf“open-mouthed”
- Anglo-Norman · derived from*baivel
- Middle English · inherited from*bevel
- English todaybevel
From Middle English *bevel, from Anglo-Norman *baivel (whence obsolete French beauveau) a diminutive of Old French baïf (“open-mouthed”), perhaps from baer (“to gape”), from Medieval Latin *batāre (“to gape, yawn, be open”), probably of imitative origin. If so, then related to Italian badare.
Etymology from Wiktionary, CC BY-SA 4.0.