The word demonetises 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: 16
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (30 words)
dements, demesne, demises, demists, demotes, denoise, denotes, densest, destine, dimness, dissent, endmost, enemies, esteems, meioses, mindset, misdoes, misdone, mitoses, moisten, nemesis, nosiest, onetime, seitens, sestine, siemens, snidest, somites, stenose, stomies