The word contravenes 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
Seven Letter Word Alert: (74 words)
acerose, acetone, atoners, canoers, canteen, canters, cantons, cantors, careens, cartons, carvone, caverns, cavorts, cenotes, centers, centres, cerates, coarsen, coaster, consent, convene, convent, convert, corneas, cornets, coverts, coveter, cratons, creates, earnest, eastern, enactor, encores, ensnare, estrone, evocate, nascent, nearest, neatens, necrose, nectars, neonate, nonarts, octanes, octaves, octenes, overact, overate, overeat, oversat, oversea, overset, recanes, recants, recoats, reenact, rennets, revotes, roseate, scanner, scanter, scenter, senator, servant, sterane, tanners, taverns, tenners, trances, treason, vectors, veteran, vetoers, voteens