The word desalinises 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: 14
Highest Scoring Words With Friends™ Play In The Letters desalinises
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Seven Letter Word Alert: (26 words)
aediles, aidless, anilide, aniseed, dailies, daisies, denials, diesels, disease, eleidin, endless, enseals, insides, islands, lassies, lessens, liaised, liaises, linseed, sadness, salines, seaside, sessile, silanes, sinless, snailed