The word centesimal 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: 18
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (46 words)
ailment, aliment, amnesic, calmest, cantles, castile, cements, cinemas, cleanse, clement, clients, climate, elastic, elastin, emetics, enamels, encalms, entails, entices, icemans, inmates, laciest, laments, lancets, lateens, leanest, lenites, license, lineate, malices, mantels, mantles, matinee, meanest, meanies, menaces, metical, nailset, nematic, netmail, salient, scalene, seminal, silence, stencil, tensile