belly out

verb2

1. •
   To bulge or billow outward.

   • The most considerable and most elevated parts consist of six columns, the capitals of three of which belly out, while those of the three others, which are parallel to them, are guttered […] — 1803
2. •
   To cause to bulge or billow outward.

   • The scene is changed and Fortune’s gale Shall belly out each prosperous sail. — 1834