Added 9 October 2026 billowing adjective Categories: Describing WordsRare Words adjective ! Definition from WordNet 3.1, Princeton University. More about billowing at Wordnik → Where our words come from → Characterized by great swelling waves or surges. billowy storm clouds Related Words: surgingtumblingstormymovingrollingmountingescalatingbellyingblowingundulationefflationbubbling Back to today's word