Etymology
From Middle English belwes, plural of belu, belwe, a northern form of beli, from Old English bæliġ, northern form of bielġ, from Proto-Germanic *balgiz. Compare German Balg. See also belly. For the pronunciation /ˈbɛl.əs/, compare bodice, gallows.
Definitions & examples from Wiktionary (CC BY-SA 3.0).