The word centroidal 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: 16
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (58 words)
aconite, aileron, aloetic, aneroid, article, cairned, caldron, calorie, candler, cantred, caroled, carotid, central, certain, citadel, clarion, coalier, coalite, cordate, cordial, corneal, cotidal, decalin, decrial, delator, deltaic, detrain, dialect, dilater, dilator, elation, enactor, erotica, lactone, latrine, lection, leotard, located, noticed, oracled, ordinal, otarine, radicel, radicle, ratline, recital, reliant, retinal, retinol, tacnode, talonid, tendril, toenail, tradein, trailed, trained, tranced, trenail