The word stoppering 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™ Plays In The Letters stoppering
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Seven Letter Word Alert: (42 words)
egotrip, goiters, goitres, goriest, ignores, nippers, norites, orients, pigeons, pigpens, pingers, pingoes, pointer, porting, postern, posting, potpies, pronest, propine, protein, pterins, regions, repoint, resting, ripstop, ropiest, snipper, snippet, soppier, sopping, sorting, sponger, sporing, stinger, stonier, stopper, storing, tippers, toppers, topping, topspin, triones