The word disinfesting 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™ Plays In The Letters disinfesting
:
Seven Letter Word Alert: (35 words)
denting, dentins, designs, dieting, digests, dingies, dinting, dissent, dissing, editing, endings, ensigns, fending, fidgets, finding, finings, fitness, ignited, ignites, indents, indites, infests, ingests, insides, intends, nesting, sending, sensing, sidings, sifting, signets, snidest, tending, tensing, tidings