The word pluralising 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™ Plays In The Letters pluralising
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Seven Letter Word Alert: (38 words)
airguns, airings, aisling, arillus, arising, aspirin, insular, lairing, langurs, lapsing, lingual, lisping, lugsail, pairing, palling, parings, parsing, pausing, pilings, pillars, plugins, plurals, pulling, pulsing, purlins, pursing, railing, raising, rasping, rulings, sailing, sapling, sparing, spiring, ungrasp, unpairs, uprisal, urinals