The word certainties 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: 15
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (89 words)
aeriest, airiest, antsier, arcsine, arenite, arsenic, artiest, attires, canters, careens, carnies, cattier, centers, centres, cerates, certain, cistern, citrate, citrine, cittern, creates, cretins, cristae, earnest, eastern, enteric, enticer, entices, entreat, entries, inciter, incites, inertia, instate, iratest, irenics, irisate, iterate, nastier, natters, nattier, nearest, neatest, nectars, netters, nictate, nitrate, nitrite, nittier, raciest, recanes, recants, recites, reenact, restain, restate, retains, retaste, retinas, retints, satiric, scanter, scatter, scenter, seriate, sericin, sincere, stainer, statice, sterane, straint, striate, tantric, tastier, tenters, tentier, ternate, testier, tetanic, tiniest, tinters, tintier, titanic, trainee, trances, transit, triaene, trienes, trisect