The word diphenylhydantoin cannot be made in Words With Friends™. It is 17 letters long, too long to fit on a WordsWithFriends board (15 letters max).
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (106 words)
adenoid, adeptly, adipoid, adopted, anilide, aniline, annelid, annoyed, anodyne, antlion, aplenty, athodyd, dandily, daytide, deathly, deltoid, diethyl, dilated, diploid, diptail, diynone, dolphin, donated, edition, elation, endplay, ethanol, ethynyl, handily, handled, haplite, haploid, headpin, healthy, helipad, holiday, hoplite, hothead, hotline, hyaline, hyalite, hyaloid, hydatid, hypnoid, inanely, indepth, indited, ineptly, inhaled, intoned, lithoid, loathed, lyddite, nepotal, ninepin, ninthly, nondate, nondiet, nondyed, nonland, nonlate, nonlead, nonleap, nonpaid, nonplay, notedly, notepad, opaline, opiated, painted, patined, penalty, pendant, pennant, pentail, phonily, phthaly, piloted, pinhead, pinhold, pinhole, pinitol, pinnate, pintail, pithead, pithily, plaided, plaited, planned, planted, pointed, polyyne, pontine, pothead, ptyalin, tadpole, tailpin, talonid, taphole, tepidly, thinned, tiddley, tinnily, toenail, topline, typhoid