The word centripetal 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™ Play In The Letters
Seven Letter Word Alert: (88 words)
arenite, article, caliper, cantrip, cattier, central, certain, citrate, cittern, clatter, cleaner, clipart, clitter, enteral, enteric, enticer, entitle, entreat, eternal, inepter, inplace, iterate, latrine, lattice, lectern, lineate, nattier, nictate, nitrate, painter, palette, panicle, patient, pattern, peatier, pectate, pelican, peltate, penlite, pentail, percent, perlite, pertain, pettier, picante, picrate, plainer, planter, platter, plicate, praline, prattle, precent, prelate, prelect, ratline, receipt, recital, reclean, recline, reenact, reliant, repaint, repanel, replace, replait, replane, replant, replate, repleat, replica, reptile, retinal, retitle, tactile, tantric, tentier, ternate, terpine, tertial, tetanic, tipcart, trainee, treacle, trenail, triaene, triplet, triptan