The word defaulters 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™ Plays In The Letters
Seven Letter Word Alert: (59 words)
alerted, altered, auletes, austere, deafest, dealers, dearest, default, defeats, deflate, defleas, defuser, delates, draftee, duelers, earfuls, elaters, eluated, eluates, eluders, estrual, euaster, falters, fardels, faulted, feasted, feature, federal, fluster, fluters, fuelers, leaders, realest, reasted, redates, redeals, redealt, reflate, refuels, refusal, refused, refutal, refuted, refutes, related, relates, restful, rustled, saluted, saluter, sauteed, sedater, stealer, strudel, sulfate, tasered, tearful, treadle, treeful