The word demagnetises 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: (91 words)
aniseed, deeming, degases, demasts, demates, demeans, dements, demesne, demises, demists, densest, designs, desmans, destain, destine, detains, digests, dimness, disease, dissent, easiest, edgiest, endgame, enemies, enigmas, esteems, gametes, gamiest, gatemen, geneses, genesis, ingests, inmates, inseams, instead, madness, magnets, maidens, massing, matinee, matings, meanest, meanies, medians, mediate, meeting, menages, message, messing, midgets, mindset, mintage, misdate, misseat, negated, negates, nemesis, sagiest, sainted, sateens, seaming, seaside, seating, sedates, seeding, seeming, segment, seitans, seitens, senates, sensate, sestina, sestine, siamese, sideman, siemens, sigmate, signees, signets, smidgen, snidest, stained, stamens, standee, steamed, stigmas, tandems, teaming, teasing, teeming, teenage