The word plasticine 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: 18
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (49 words)
alpines, aplites, aplitic, aseptic, cantles, caplets, castile, catnips, ciliate, clients, elastic, elastin, elicits, enclasp, entails, icepail, incites, inclasp, inplace, inscape, inspect, italics, laciest, laicise, lancets, nailset, panicle, panties, patines, pectins, pelican, pelitic, pencils, pentail, pianist, picante, pilates, pintail, planets, plastic, plicate, salient, spaniel, special, spicate, splenic, stencil, tailpin, tiepins