late 14c., verbal noun from bellow (v.). As a present-participle adjective, recorded from 1610s.
Entries linking to bellowing
bellow v.
early 14c., apparently from Old English bylgan "to bellow," from an imitative PIE root *bhel-"to sound, roar." Originally of animals, especially cows and bulls; used of human beings since c. 1600. Related: Bellowed; bellowing. As a noun, "a loud, deep cry," from 1763.