The word marginalise 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: (77 words)
aerials, airings, airline, airmail, aisling, aligner, amnesia, anglers, animals, arising, arsenal, enigmas, erasing, gainers, galenas, geminal, genials, girlies, girnels, gmelina, gremlin, imagers, imagine, laagers, lairing, laminae, laminar, laminas, lasagne, learing, leasing, lingers, mailers, mailing, malaise, maligns, manager, manages, mangers, mangier, mangler, mangles, manlier, margins, marinas, marines, marlins, mineral, mingler, mingles, mirages, nailers, railing, raising, realign, realism, reaming, regains, regalia, remails, remains, renails, sailing, sangria, sealing, seaming, searing, seminal, seminar, similar, siriema, sirname, slimier, sliming, slinger, smilier, smiling