The word grassfinches 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: 23
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (75 words)
ancress, arching, arcsine, arsenic, arshine, arshins, assigns, carnies, caseins, cashers, cashier, cashing, casings, ceasing, chafers, chafing, chagrin, chainer, chaises, changer, changes, charges, chasers, chasing, chassis, crashes, cringes, erasing, facings, fancier, fancies, fearing, fiances, finches, fingers, fishers, fringes, gainers, garfish, garnish, gashers, gassers, gassier, geishas, gnasher, gnashes, grasses, hangers, harness, hearing, hernias, hissers, inchers, ingress, inreach, ragfish, ranches, rechain, regains, rehangs, rescans, resigns, sashing, sassier, sassing, scaring, searing, sharing, sherifs, shiners, shrines, sighers, signers, singers, sringas