The word christianise 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: 18
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (92 words)
achiest, actress, airiest, aitches, ancress, anthers, antsier, arcsine, arsenic, arshine, arshins, ascents, ascites, ashiest, canters, carnies, caseins, cashers, cashier, casters, certain, chainer, chaises, chanter, chasers, chasten, chaster, cistern, cithern, cithers, citrine, crashes, cretins, cristae, ethnics, hairnet, harness, hastens, hastier, hernias, hissier, ichnite, iciness, incests, inchers, incises, inciter, incites, inertia, inherit, inreach, insects, inserts, instars, irenics, irisate, itchier, nastier, nectars, raciest, racists, raisins, ranches, rashest, recants, recasts, rechain, rescans, restain, retains, retinas, richest, sachets, satires, satiric, scanter, scathes, secants, seitans, sericin, sestina, shiners, shinier, shrines, sinters, stainer, stances, strains, tarnish, trances, tranche, trashes