The word circumvallate 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: 29
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (67 words)
acclaim, accrual, acerval, acicula, activer, aircell, alltime, alluvia, amateur, arcuate, article, auricle, avarice, cacemia, calcite, calcium, calculi, calicle, calumet, caramel, catcall, caviler, ceramic, circlet, claimer, clavate, clavier, climate, crucial, culvert, cureall, curtail, cuticle, eluvial, lacteal, lateral, literal, macular, mailcar, maltier, marital, marlite, martial, metical, micella, miracle, mullite, muriate, racemic, reavail, recital, reclaim, rivulet, tallier, tramell, travail, tumeric, uraemia, uraemic, uralite, valuate, variate, vaulter, velaria, velaric, victual, virtual