The word weightlessness is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 23
Highest Scoring Words With Friends™ Play In The Letters weightlessness
:
Seven Letter Word Alert: (64 words)
elegies, elegise, elegist, elegits, english, enlight, enlists, ethenes, geneses, genesis, gentile, gentles, glisten, heeling, hessite, ingests, lengths, lenites, lessees, lessens, lighten, listens, nestles, netless, seethes, seitens, sessile, sestine, sewings, shewing, shingle, signees, signets, silents, singles, singlet, sinless, sleighs, sleight, slewing, slights, steelie, stewing, sweeten, sweetie, swishes, tensile, tieless, tingles, tinsels, twinges, weights, welting, wetness, wheelie, whinges, whistle, whitens, wigless, wiglets, winglet, winless, witless, witness