The word reaffirming 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: 23
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (26 words)
angrier, earring, fairing, farming, fearing, firearm, fireman, firming, firring, framing, fringer, giraffe, grainer, griffin, grimier, imagine, mangier, mariner, marring, rainier, rangier, reaming, rearing, reffing, refrain, rimfire