The word decalcifying 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: 28
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (42 words)
accinge, acidify, aclinic, aedilic, alginic, aligned, angelic, anglify, anilide, calcify, calcine, ceiling, clanged, cyanide, cyclane, cycling, cynical, dealign, dealing, decalin, defying, deicing, dialing, dicycle, dignify, dingily, eliding, failing, fancied, fancily, finagle, flaccid, flanged, flaying, glanced, glycine, infidel, infield, leading, leafing, lignify, yealing