weightless

ethereal inconsequential trivial

agile airy atmospheric buoyant crumbly dainty delicate downy easy effervescent featherweight feathery filmy flimsy floatable floating fluffy friable frothy gossamery graceful imponderous insubstantial light as a feather light-footed lightweight lithe little loose meager nimble petty porous portable sandy sheer slender slight small spongy sprightly sylphlike thin tissuelike trifling unheavy unsubstantial

important significant