The word unobserved 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: 20
Highest Scoring Words With Friends™ Play In The Letters unobserved
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Seven Letter Word Alert: (33 words)
bedsore, benders, boreens, bounder, burdens, deboner, debones, devours, enbused, endorse, endures, enrobed, enrobes, ensured, nervous, observe, obverse, overdub, overdue, overuse, rebonds, rebound, resound, rosebud, sobered, sounder, subnode, subvene, undoers, unrobed, unrobes, vendors, verbose