The word grandmaster 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: (64 words)
agendas, argents, armrest, arrange, artsman, artsmen, damager, damages, damners, dangers, darners, darters, dragnet, eartags, errands, errants, ganders, gardens, garment, garners, garnets, garrets, garters, gateman, gnarred, gradate, graders, grander, grandma, granted, granter, graters, magenta, magnate, magnets, managed, manager, manages, mandate, mangers, mantras, margate, martens, megarad, nametag, narrate, rangers, ranters, redrags, regards, regrant, remands, retards, smarted, smarten, smarter, stander, starred, strange, tanager, tandems, tangram, teargas, traders