The word intertidal 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: 13
Highest Scoring Words With Friends™ Plays In The Letters intertidal
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Seven Letter Word Alert: (29 words)
airline, anilide, attired, deliria, denarii, detrain, dilater, inditer, inertia, latrine, lintier, nattier, nitrate, nitride, nitrite, nittier, ratline, rattled, reliant, retinal, tainted, tendril, tertial, tintier, tradein, trailed, trained, trenail, trident