The word posturers 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: 13
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (32 words)
estrous, oestrus, ousters, porters, poseurs, posters, posture, pourers, pouters, presort, pursers, reports, reposts, repours, resorps, resorts, respots, retours, rosters, routers, sorters, sourest, spouter, sprouts, spurter, stupers, stupors, toruses, tourers, trouper, troupes, trouser