The word demagnetised 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: (70 words)
amended, aniseed, dandies, deadens, deadest, deadmen, deeding, deeming, demands, demated, demates, demeans, dements, demesne, demised, destain, destine, detains, diadems, distend, edgiest, emended, endgame, enemies, enigmas, gametes, gamiest, gatemen, inmates, instead, maddens, maddest, madding, magnets, maidens, matinee, matings, meanest, meanies, medians, mediate, meeting, menages, middens, midgets, mindset, mintage, misdate, misdeed, negated, negates, sainted, seaming, seating, sedated, seeding, seeming, segment, sideman, sigmate, smidgen, stained, standee, steamed, tandems, teaming, teasing, teddies, teeming, teenage