The word officialising 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: 26
Highest Scoring Words With Friends™ Play In The Letters officialising
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Seven Letter Word Alert: (26 words)
agnosic, aisling, alginic, closing, coaling, coffins, coiling, facings, failing, falcons, filings, finials, foaling, foiling, goniffs, lacings, liaison, loafing, nicosia, oilcans, sailing, scaling, signoff, silicon, slicing, soiling