The word laundresses 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: 15
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (47 words)
assured, assures, asunder, dealers, dresses, duelers, earless, eldress, eluders, endears, endless, endures, enlards, enseals, ensears, ensured, ensures, landers, launder, leaders, leaners, learned, leasers, lenders, lessens, redeals, redness, resales, resands, reseals, resends, sadness, sanders, sealers, senders, sensual, slander, slender, snarled, sudsers, sundaes, sunless, undress, unreels, unseals, ureases, useless