Without weight, having comparatively little weight. Also (of a body having mass), not apparently acted on by gravity, either because the…

Without weight; very light.

Having no appreciable weight; of extremely small weight or amount.

loosely. Having no appreciable weight; ‘weightless’; extremely light.

(Stress variable.) Extremely lightweight; spec. applied to a small, low-speed, inexpensive, usually one-seater aircraft that has a small engine but…