The word marginalising 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: 23
Highest Scoring Words With Friends™ Play In The Letters marginalising
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Seven Letter Word Alert: (43 words)
airings, airmail, aisling, anginal, anginas, angling, animals, arising, gaining, ganglia, girling, girning, glaring, griming, imaging, ingrain, lairing, laminar, laminas, lignins, limning, linings, mailing, maligns, margins, marinas, marlins, nailing, railing, raining, raising, ranging, ringing, ringman, rinsing, sailing, sangria, signing, similar, singing, sliming, smiling, snaring