The word teaspoonful 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: 20
Highest Scoring Words With Friends™ Play In The Letters teaspoonful
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Seven Letter Word Alert: (31 words)
apostle, eluants, fanouts, festoon, flaunts, fluents, folates, foulest, leantos, leptons, lunates, nepotal, ooplast, opulent, outleap, outplan, outsole, outspan, panfuls, peanuts, penults, planets, platoon, plutons, potfuls, pulsate, sulfate, sulfone, unloose, unspoof, upslant