The word unstableness 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: 19
Highest Scoring Words With Friends™ Plays In The Letters unstableness
:
Seven Letter Word Alert: (60 words)
abluent, ablutes, absents, annulet, assents, auletes, baleens, bassets, blesses, bustles, butanes, butenes, eluants, eluates, eluents, enables, enbuses, enseals, lateens, leanest, lessens, lunates, neatens, nebulae, nebulas, nestles, netless, salutes, sateens, senates, sensate, sensual, stables, sublets, subnets, subsets, sultans, sunbelt, sunless, sunsets, suntans, taluses, tassels, tealess, teasels, tenable, tubless, tunable, tunnels, tussles, unbales, unbelts, unblent, unbless, unblest, uneaten, unseals, unseats, useable, useless