oppositeness(n = noun.linkdef) opposition - the relation between opposed entities;
is a kind of relation
has particulars: antipode, antithesis, conflict, contrast, direct contrast, flip side, mutual opposition, polarity, gradable opposition, polarity, sign, ungradable opposition, contradictoriness, contradiction, contrary, contrariety, tertium quid, contrary, opposite, reverse, inverse, opposite, antagonism
Derived forms adjective opposite₆, adjective opposite₅

   The quality or state of being opposite. [1913 Webster]

N  contrariety, contrast, foil, antithesis, oppositeness, contradiction, antagonism, clashing, repugnance, inversion, the opposite, the reverse, the inverse, the converse, the antipodes, the antithesis, the other extreme, contrary, contrarious, contrariant, opposite, counter, dead against, converse, reverse, opposed, antithetical, contrasted, antipodean, antagonistic, opposing, conflicting, inconsistent, contradictory, at cross purposes, negative, hostile, differing toto coelo, diametrically opposite, diametrically opposed, as opposite as black and white, as opposite as light and darkness, as opposite as fire and water, as opposite as the poles, as different as night and day, Hyperion to a satyr, quite the contrary, quite the reverse, no such thing, just the other way, tout au contraire, contrarily, contra, contrariwise, per contra, on the contrary, nay rather, vice versa, on the other hand, all concord's born of contraries, Thesis, antithesis, synthesis.