The word ineffectiveness 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: 30
Highest Scoring Words With Friends™ Play In The Letters ineffectiveness
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Seven Letter Word Alert: (29 words)
effects, entices, essence, evenest, evictee, evinces, festive, fictive, fifteen, fifties, finesse, fitness, iciness, incense, incests, incises, incites, infects, infests, insects, intense, invects, invents, invests, invitee, invites, seitens, sestine, stiffen