The Collaborative International Dictionary of English v.0.48:
Unlawful \Un*law"ful\, a. Not lawful; contrary to law. -- Un*law"ful*ly, adv. -- Un*law"ful*ness, n. [1913 Webster] Unlawful assembly. (Law) See under Assembly. [1913 Webster]WordNet (r) 3.0 (2006):
unlawfulness n 1: the quality of failing to conform to law [ant: lawfulness]