belly

Inherited from Middle English bely, beli, bali, below, belew, balyw, from Old English bielġ (“bag, pouch, bulge”), from Proto-West Germanic *balgi, *balgu, from Proto-Germanic *balgiz, *balguz (“skin, hide, bellows, bag”), from Proto-Indo-European *bʰelǵʰ- (“to swell, blow up”). Cognate with Dutch balg, German Balg, Danish bælg, Old Irish bolg, Welsh bol. Doublet of bellows, blague, bulge, and budge. See also bellows.

For the belly — bellows relation, compare typologically Macedonian мев (mev, “abdomen, belly; bellows”). Also compare Ancient Greek φῦσα (phûsa, “bellows; bladder; ...”), Latin venter — vēsīca, Russian пу́зо (púzo) — пузы́рь (puzýrʹ), пузырёк (puzyrjók).