The word unchangingness 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: 28
Highest Scoring Words With Friends™ Play In The Letters unchangingness
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Seven Letter Word Alert: (40 words)
anguish, canines, canning, caseins, cashing, casings, causing, ceasing, chaises, changes, chasing, cunning, cussing, enchain, ensigns, ensuing, gashing, gassing, geishas, ginseng, gnashes, guanine, guineas, gunning, gushing, hanging, nannies, nuances, sashing, saucing, seguing, sensing, siennas, signage, sunnies, sunning, unaging, uncages, unchain, unhinge