unlikeness(n = noun.attribute) dissimilitude - dissimilarity evidenced by an absence of likeness; Array
is a kind of dissimilarity, unsimilarity
Antonym: likeness
Derived form adjective unlike₁

   The quality or state of being unlike; want of resemblance; dissimilarity. Tennyson. [1913 Webster]

N  dissimilarity, dissimilaritude, unlikeness, diversity, disparity, dissemblance, divergence, variation, difference, novelty, originality, creativeness, oogamy, dissimilar, unlike, disparate, divergent, of a different kind, unmatched, unique, new, novel, unprecedented, original, nothing of the kind, no such thing, quite another thing, far from it, cast in a different mold, tertium quid, as like a dock as a daisy, very like a whale, as different as chalk from cheese, as different as Macedon and Monmouth, lucus a non lucendo, diversified, otherwise, diis aliter visum, no more like my father than I to Hercules.