BILLOW

[verb] [I] - to spread over a large area, or (esp. of items made of cloth) to become filled with air and appear to be largerSmoke billowed (out) from the burning building.The sheets/shirts hanging on the line billowed in the breeze.We watched the boats with their billowing sails.(figurative) Their small disagreement soon billowed (= quickly grew larger) into a more serious conflict.(figurative) Billowing (= Quickly increasing) corruption was one of the factors which led to civil war.