The word incompetency 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: 28
Highest Scoring Words With Friends™ Plays In The Letters incompetency
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Seven Letter Word Alert: (27 words)
cometic, compete, conceit, concept, connect, ecotype, ectopic, eminent, enocyte, epicyte, epitome, inocyte, meconic, mention, miocene, mycotic, neocyte, neotype, nepotic, nominee, nonepic, onetime, pentyne, pimento, pontine, ponymen, potency