on the hot seat (adjective) behind the eight ball: in a jam
Sinonime: agile, airy, atmospheric, buoyant, crumbly, dainty, delicate, downy, easy, effervescent, ethereal, featherweight, feathery, filmy, flimsy, floatable, floating*, fluffy, friable, frothy, gossamery, graceful, imponderous, inconsequential, 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, trivial, unheavy, unsubstantial