The word centreboard 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: 19
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (57 words)
aborted, abortee, aborter, acetone, adorner, arbored, barcode, baronet, barreed, bartend, berated, boarder, bracted, brander, broaden, broader, brocade, cantred, carbeen, carbene, catered, caterer, centred, cerebra, cordate, created, creator, debater, deboner, enacted, enactor, encoder, encored, enrobed, enrober, erector, ornater, reacted, reactor, readorn, rebated, rebater, reboard, rebored, rebrace, rebrand, recaned, recrate, reenact, retrace, retrade, retread, tacnode, terrace, terrane, tranced, treader