The word groundlings 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: 20
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (25 words)
dilogun, dousing, droning, dunging, gosling, grounds, gundogs, gurning, lodging, longing, longrun, lousing, lunging, nondrug, nudging, nursing, roguing, rousing, rulings, snoring, souring, surging, undoing, unsling, urgings