The word cocksureness 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: 24
Highest Scoring Words With Friends™ Play In The Letters cocksureness
:
Seven Letter Word Alert: (32 words)
censers, censors, censure, coerces, concurs, concuss, conkers, courses, cresses, crosses, cussers, encores, ensures, necrose, reckons, recocks, recuses, rescues, sconces, screens, secerns, secures, sensors, soccers, sources, success, succors, suckers, sucrose, uncocks, uncorks, uncross