The word evaporites 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: 17
Highest Scoring Words With Friends™ Play In The Letters evaporites
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Seven Letter Word Alert: (38 words)
aeriest, erosive, erotise, etaerio, operate, opiates, ovaries, overate, overeat, oversat, oversea, overset, oversit, overtip, parties, pastier, peatier, pirates, pivoter, poetise, private, repaste, repaves, repeats, repivot, respite, restive, retapes, revotes, ropiest, roseate, seaport, seriate, sievert, soapier, traipse, veritas, vetoers