The word quincentennials 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: 33
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (99 words)
acquest, acquist, acquits, ancient, aniline, annulet, antique, asinine, auletes, aunties, calques, canines, canteen, cantles, castile, catenin, cauline, ciliate, cleanse, clients, cliques, cuisine, cuneate, cutline, elastic, elastin, elicits, eluants, eluates, eluents, ensuite, entails, entices, equates, equines, euclase, incants, incense, incites, incline, inlines, inquest, inquiet, insulin, intense, inulase, inulins, italics, laciest, laicise, lancets, lateens, leanest, lenient, lenites, leucine, leucite, license, lineate, linnets, lucites, lunates, lunatic, luniest, nailset, nannies, nascent, neatens, niacins, nuances, nutcase, quantic, quiesce, quieten, quinces, quinine, quintic, salient, scalene, sequela, sequent, silence, siliqua, silique, sinuate, stannic, stencil, sulcate, tannins, tensile, tequila, tunnels, unclean, uneaten, unities, unlaces, unstain, utensil, utilise