The word guiltiness 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: 15
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (31 words)
eluting, enlists, glisten, gluiest, glutens, gunless, gutless, ignites, ingests, insults, issuing, lignite, listens, listing, luniest, lusting, signets, silents, silting, singles, singlet, suiting, tilings, tingles, tinsels, tugless, ugliest, unities, unlists, utensil, utilise