The word reassurance 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: 16
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (35 words)
ancress, careens, careers, causers, censers, censure, crasser, creaser, creases, cursers, earners, encases, ensears, ensurer, ensures, erasers, erasure, nursers, recanes, recures, recurse, recuses, rescans, rescuer, rescues, saucers, scarers, screens, seances, secerns, securer, secures, snarers, sucrase, ureases