The word hibernates 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: (55 words)
absinth, aeriest, anthers, antsier, arenite, arsheen, arshine, atheise, baiters, banshee, banters, barites, bathers, beanies, bearish, beaters, beerish, beneath, berates, breathe, breaths, earnest, earthen, eastern, entries, ethanes, hairnet, hasbeen, hastier, hearten, heaters, herbist, hernias, nastier, nearest, neither, rebaits, rebates, rebathe, rebaths, rebites, reheats, reshine, restain, retains, retinas, seriate, sherbet, stainer, sterane, tarnish, therein, trainee, triaene, trienes