The word prologising 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 prologising
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Seven Letter Word Alert: (24 words)
gigolos, girling, goosing, gorgons, gosling, griping, groping, lisping, looping, loosing, origins, pilings, plosion, poising, pooling, prologs, prolong, roiling, sirloin, sloping, soiling, soloing, spiring, sporing