The word highwaters 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: 19
Highest Scoring Words With Friends™ Play In The Letters highwaters
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Seven Letter Word Alert: (23 words)
aigrets, earwigs, eighths, gaiters, gathers, hastier, hearths, heights, highest, resight, rethaws, sighter, stagier, triages, waiters, wariest, wearish, weights, whither, withers, wraiths, wreaths, writhes