The word dekametres 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™ Play In The Letters
Seven Letter Word Alert: (31 words)
darkest, dearest, demarks, demates, emersed, markets, meekest, meerkat, meeters, metered, readmes, reasked, reasted, redates, redeems, reested, remakes, remated, remates, remeets, restake, retakes, reteams, sedater, smarted, smeared, steamed, steamer, steered, tasered, teemers