The word musculature 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: 21
Highest Scoring Words With Friends™ Play In The Letters musculature
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Seven Letter Word Alert: (30 words)
amulets, armlets, auscult, auteurs, calmest, calumet, cartels, cauters, clarets, cluster, crustal, culture, cumular, cumulus, curates, estrual, macules, matures, maulers, mutuals, rectums, recusal, saluter, scarlet, secular, serumal, sulcate, sutural, tramels, umlauts