The word careerists 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: 13
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (54 words)
actress, aeriest, arrests, artsier, ascites, careers, carries, carters, casters, caterer, cerates, cerises, crasser, craters, creaser, creases, creates, cresset, cristae, easiest, erasers, erratic, raciest, racists, raisers, rasters, rearise, recasts, reciter, recites, recrate, reseats, resects, resters, restirs, retears, retires, retrace, retries, satires, scarers, scarier, seaters, secrets, seriate, serrate, sierras, starers, tarries, tearers, tearier, teasers, terrace, tracers