The word diagonalises 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: 17
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (91 words)
adonise, aeolian, agendas, agnosia, agonies, agonise, aidless, aisling, aldoses, aliased, aliases, aligned, analogs, angioid, anilide, anodise, dailies, daisies, dalasis, dangles, dealign, dealing, denials, designs, dialing, dialogs, dingies, dissing, dogless, doilies, dosages, eliding, elision, eloigns, galenas, genials, geoidal, glassed, glioses, gliosis, glossed, goalies, godless, goldens, gonadal, idolise, indigos, indoles, insides, insoles, iodines, iodises, ionised, ionises, islands, ladings, lasagne, lassoed, leading, leasing, legions, lesions, liaised, liaises, liaison, ligands, ligases, lingoes, lioness, lionise, loading, losings, oldness, sailing, salines, sandals, seadogs, sealing, sealion, sidings, sidling, signals, silanes, singled, singles, sinoids, slanged, sliding, slogans, snailed, soiling