The word jackrabbited 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: 35
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (23 words)
abreact, airdate, backbar, backbit, batiked, batiker, bedtick, bracket, bracted, bricked, cabaret, carbide, catbird, crabbed, cribbed, decabit, dieback, radiate, tackier, tiaraed, tieback, tracked, tricked