The word inscrutability 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: 25
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (66 words)
ability, albinic, albitic, bairnly, biliary, biscuit, blastic, bristly, bucinas, burials, cattily, ciliary, citrusy, clarity, crustal, crystal, cultist, curably, curials, curtail, curtain, incrust, initial, insular, intrust, intuits, italics, lunatic, nastily, nattily, nitryls, raucity, rituals, rustily, saintly, satiric, saucily, scantly, scarily, scribal, starlit, straint, subrail, tacitly, tantric, tastily, titanic, titular, transit, tribals, trinity, truancy, truants, truncal, trysail, tunably, turbans, tyrants, unbaits, uncarts, unitary, unsilty, untasty, urinals, utility, yttrias