The word clingstones 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: 19
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (61 words)
cession, clients, cloning, closest, closets, closing, cognise, congest, consent, consign, consist, cosiest, cosigns, cosines, costing, egoists, elogist, eloigns, enlists, ensigns, glioses, glisten, gnostic, incests, ingests, insects, insoles, intones, lection, legions, lensing, lesions, lingoes, linnets, lioness, lionets, listens, longest, losings, nesting, nosiest, notices, oecists, ossicle, section, sensing, signets, silents, singles, singlet, sonnets, stencil, stogies, stoning, tensing, tension, tingles, tinsels, tocsins, tonsils, tossing