← BackshareGuessbillowy/ˈbɪloʊi/adjectiveHaving a wavy, swelling, or puffy shape, like a large wave or cloud.She wore a dress with billowy sleeves that fluttered in the breeze.The ship sailed through billowy seas during the storm.The billowy clouds drifted slowly across the summer sky.SynonymsswellingwavypuffyAntonymssmoothflat