The word contravening 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: 24
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (61 words)
aconite, activer, ancient, antigen, atoning, cannier, canning, canting, carting, carving, carvone, catenin, catogen, certain, coating, cognate, coinage, conning, connive, contain, convent, convert, coreign, corning, craning, crating, craving, earning, enactor, entrain, environ, erotica, evictor, gentian, granite, ingrate, intoner, ironage, nearing, nerving, orating, organic, otarine, overact, ranting, reaving, regnant, renting, roaning, tangier, tanning, tearing, tonnage, tracing, vearing, venting, vertigo, vetoing, vinegar, vintage, vintner