The word attoseconds 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™ Play In The Letters attoseconds
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Seven Letter Word Alert: (30 words)
acnodes, ascends, ascents, attends, cassoon, coasted, codetta, contest, costate, cottons, deacons, decants, descant, donates, nosodes, notated, octanes, octants, osteons, scatted, scooted, secants, seconds, snooted, snotted, soonest, stances, stetson, tacnode, toasted