The word lasciviousness 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
Seven Letter Word Alert: (79 words)
alcoves, avionic, caisson, caseins, casinos, cassons, cauline, celosia, celsius, cession, classes, clauses, coalise, consuls, cosines, counsel, cousins, covines, cuisine, elision, elusion, ensouls, envious, eosinic, evasion, iciness, incises, insoles, inulase, invoice, ionises, laicise, lassies, lassoes, lesions, lessons, liaises, liaison, lioness, lionise, nicosia, novices, oilcans, olivine, osseins, ossicle, sacless, salines, sealion, seasons, sensual, session, silanes, silicas, silicon, silvans, sinless, sinuses, sissies, slovens, sluices, snivels, socials, solaces, sonless, sunless, uncivil, unclose, uncoils, unlaces, unseals, unveils, vacuole, vesical, vicious, violins, viscous, visions, visuals