The word firelighters 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™ Play In The Letters
Seven Letter Word Alert: (63 words)
eighter, elegist, elegits, felsite, ferrets, ferries, ferrite, fertile, fierier, fighter, filters, firelit, fishier, flights, flirter, freight, fresher, frights, girlier, girlies, girlish, glister, grister, gristle, hefters, heftier, heifers, herself, lefties, lifters, lighter, refiles, refires, reflies, refresh, refrets, refries, regrets, rehires, reifier, reifies, reliefs, reliers, relight, reshift, resight, retiles, retires, retries, riflers, righter, shelter, shifter, sigfile, sighter, siltier, sleight, slither, sterile, stifler, tigrish, trifler, trifles