The word disgruntle 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: (68 words)
delints, dentils, diluent, diluter, dilutes, dueling, duelist, dunites, dustier, dusting, eluding, eluting, gilders, girdles, girnels, gliders, glinted, glisten, glister, gluiest, glutens, gristle, grunted, gruntle, guilder, guilted, guldens, gunters, gustier, gutsier, indulge, insured, intrude, lingers, luniest, lustier, lusting, nutsier, regilds, resting, reusing, ringlet, rudites, rulings, rusting, rustled, rutiles, singled, singlet, slinger, stinger, strudel, studier, tendril, tinders, tingled, tingler, tingles, trudgen, trudges, trundle, ugliest, undrest, uniters, untiled, untired, untried, utensil