The Collaborative International Dictionary of English v.0.48:
Unlikeness \Un*like"ness\, n. The quality or state of being unlike; want of resemblance; dissimilarity. --Tennyson. [1913 Webster]WordNet (r) 3.0 (2006):
unlikeness n 1: dissimilarity evidenced by an absence of likeness [syn: unlikeness, dissimilitude] [ant: alikeness, likeness, similitude]