The word polymorphemic 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: 33
Highest Scoring Words With Friends™ Plays In The Letters polymorphemic
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Seven Letter Word Alert: (21 words)
chipper, chomper, chopper, chromel, clipper, compile, coppery, crimple, cripple, homomer, hoppler, implore, loopier, microhm, moocher, morphic, myeloic, polemic, polymer, precool, pyloric