The word rhinoceroses 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: 18
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (63 words)
censers, censors, cerises, cession, cheerio, chooser, chooses, chorion, coheirs, coherer, coheres, coiners, corners, cornier, coroner, cosines, cronies, crooner, crosier, crosser, echoers, encores, erosion, heiress, heroics, heroine, heroins, heroise, honoree, honorer, hornier, horsier, hosiers, inchers, inshore, ironers, necrose, noosers, oncosis, onshore, rechose, recoins, recross, rehires, rehones, rehonor, rerinse, rescore, reshine, reshoes, reshore, rinsers, scorers, scorner, screens, secerns, seniors, shiners, shrines, sincere, snorers, soirees, sooners