The word chorioallantois 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: 23
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (86 words)
achiral, acholia, aclinal, actions, aircool, alcohol, alicant, allstar, anarchs, anchors, anthill, archons, arctans, artisan, atonias, atonics, cahoots, cantors, carinal, cartons, cartoon, cations, chariot, chitlin, chloral, chlorin, chorals, chorion, citrons, clarion, coaltar, coastal, cohorts, colitis, collars, collins, coltish, consort, control, coolant, corolla, coronal, coronas, cranial, cratons, haricot, harlots, iconist, incisor, install, instill, ischial, italics, lacinia, lariats, liaison, locator, lotions, nicosia, nostril, oilcans, ooliths, oolitic, oration, ostrich, racoons, rainhat, rations, rhotics, rosalic, satanic, satiric, scholar, scrotal, shallot, silicon, sirloin, solicit, stoical, tailors, tallish, tarnish, thralls, thrills, torsion, tsarina