The word rediscover 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: (37 words)
ceroids, cervids, cervoid, codrive, covered, coverer, crosier, decrier, decries, deicers, deriver, derives, derries, desirer, devices, deviser, devisor, diocese, diverse, divorce, drivers, erosive, overrid, recodes, records, recover, redries, redrive, rescore, resider, revised, reviser, revoice, rivered, service, voicers, voiders