The word underplayed 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: 21
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (37 words)
dandler, deanery, delayed, delayer, deluder, denuder, deplane, endplay, endured, launder, laundry, layered, learned, paddler, paneled, pearled, pedaled, peddler, pleaded, pleader, plenary, pleurae, plunder, predeal, prelude, puddler, relayed, repanel, repayed, replane, replead, undrape, unlayer, unready, upended, yearend, yearned