The word underdrawers 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: 19
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (37 words)
asunder, danders, darners, deadens, denuder, denudes, drawers, dreader, dresden, earners, endears, endured, endures, ensured, ensurer, erasure, errands, readers, reddens, redrawn, redraws, renders, rereads, resawed, reswear, rewards, rudders, sunward, swarded, swearer, unswear, wadders, wanders, wardens, warders, warners, wearers