The word carrageenins 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: 19
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (56 words)
acreage, agarics, anginas, angrier, arcsine, arraign, arrange, arsenic, canines, cannier, careens, careers, carinae, carnage, carnies, carries, ceasing, craning, creaser, cringer, cringes, earners, earning, earring, engines, enrages, ensnare, erasing, gainers, garners, generic, girners, grainer, greaser, greisen, grinner, incense, insaner, nearing, rangers, rangier, rearing, rearise, recanes, regains, regears, reigner, rerinse, ringers, sangria, scanner, scarier, scaring, searing, sincere, snaring