weightless

CIDE DICTIONARY

weightless, a. 

 Having no weight; imponderable; hence, light.  Shak.  [1913 Webster]

OXFORD DICTIONARY

weightless, adj. (of a body, esp. in an orbiting spacecraft etc.) not apparently acted on by gravity.

Derivative

weightlessly adv. weightlessness n.

THESAURUS

weightless

airy, bodiless, bubbly, downy, ethereal, featherweight, feathery, fluffy, foamy, frothy, gossamery, immaterial, impalpable, imponderable, imponderous, incorporeal, insubstantial, intangible, leger, light, light as air, lighter than vanity, lightweight, mousse, nonsubstantial, souffle, unconcrete, unheavy, unsolid, unsubstanced, unsubstantial, volatile, yeasty

ROGET THESAURUS

weightless

Levity

N levity, lightness, imponderability, buoyancy, volatility, feather, dust, mote, down, thistle, down, flue, cobweb, gossamer, straw, cork, bubble, balloon, float, buoy, ether, air, leaven, ferment, barm, yeast, lighter-than-air balloon, helium balloon, hydrogen balloon, hot air balloon, convection, thermal draft, thermal, light, subtile, airy, imponderous, imponderable, astatic, weightless, ethereal, sublimated, gossamery, suberose, suberous, uncompressed, volatile, buoyant, floating, portable, light as a feather, light as a thistle, light as air, lighter than air, rise like a balloon, float like a balloon.