The word filamentous 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: 20
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (78 words)
ailment, aliment, amounts, amulets, animose, atomise, aunties, elastin, elation, eluants, elusion, elution, emulant, emulsin, entails, famines, fanouts, faunist, filmset, finales, fistula, fistule, flaunts, flotsam, fluents, folates, foliate, foliums, foments, foulest, fulsome, fumiest, fustian, inflame, inflate, inmates, inulase, isolate, laments, leantos, leftism, lionets, lunates, luniest, maltose, mantels, mantles, mensual, minuets, minutes, misfuel, mistune, moisten, moulins, mountie, munites, nailset, netmail, nutmeal, olefins, outlies, outline, outmans, outsail, salient, sealion, seminal, sinuate, solanum, sulfate, sulfite, sulfone, tinfuls, toenail, tsunami, unmates, unsmelt, utensil