The word mongrelises 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 mongrelises
:
Seven Letter Word Alert: (64 words)
egoisms, egoless, elogies, eloigns, engross, gemless, genesis, genomes, girnels, glioses, glories, glosser, greisen, gremlin, ignores, ingress, insoles, isomere, isomers, leering, legions, lesions, lingers, lingoes, lioness, losings, lossier, meioses, messier, messing, mingler, mingles, mongers, mongrel, morsels, mossier, mossing, negroes, nemesis, reeling, regimen, regimes, regions, regloss, relines, remiges, remines, resigns, resoils, resoles, rimless, seeming, semilog, seniors, sermons, siemens, signees, signers, signors, singers, singles, slinger, smilers, soirees