The word illicitness 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: 17
Highest Scoring Words With Friends™ Play In The Letters illicitness
:
Seven Letter Word Alert: (22 words)
cellist, clients, elicits, enlists, iciness, ileitis, illicit, illites, illitic, illness, incests, incises, incites, insects, instill, lentils, lintels, listens, silents, silicle, stencil, tinsels