The word vainglorious 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: 21
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (41 words)
airguns, airings, aisling, arising, insular, lagoons, lairing, languor, langurs, liaison, livings, loosing, lousing, origins, railing, raising, ravings, ravioli, raviolo, roiling, rousing, rulings, sailing, salving, saviour, signora, sirloin, slaving, soaring, soiling, soloing, solving, souring, urinals, valuing, various, vialing, violing, violins, virgins, virions