The word stepfather 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™ Plays In The Letters stepfather
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Seven Letter Word Alert: (30 words)
fathers, feather, fetters, hafters, hapters, hatters, heapers, heaters, hefters, patters, preheat, pretest, reheaps, reheats, repaste, repeats, reshape, restate, retapes, retaste, septate, shatter, spatter, tapster, tephras, tethers, theater, theatre, thereat, threats