The word fluorescences 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: 25
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (66 words)
censers, censors, censure, cloners, closers, closure, coerces, concurs, concuss, confers, confess, confuse, consuls, coulees, counsel, courses, creoles, cresols, enclose, encores, enforce, ensouls, ensures, essence, feelers, fencers, fescues, fleecer, fleeces, flenser, flenses, flounce, focuser, focuses, foresee, forseen, frescos, fucoses, fuelers, furless, necrose, occluse, oneself, ourself, reclone, reclose, recluse, recuses, refence, refocus, refuels, refuses, rescues, resoles, sconces, screens, secerns, secures, soccers, sources, succors, sucrose, sulfone, unclose, uncross, unreels