The word polymerises 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: 20
Highest Scoring Words With Friends™ Play In The Letters polymerises
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Seven Letter Word Alert: (47 words)
elopers, empires, employs, empress, epimers, episome, implore, imposer, imposes, impress, isomere, isomers, leprosy, lispers, lossier, meioses, messier, messily, miserly, misrely, morsels, mossery, mossier, ospreys, pieless, poesies, polymer, prelims, premise, premiss, promise, repiles, replies, reposes, resoils, resoles, rimless, simpers, simpler, simples, slopers, smilers, smileys, soirees, spoiler, yelmers, yelpers