%unicity%

n. [ L. unicus single. See Unique. ] The condition of being united; quality of the unique; unification. [ 1913 Webster ]

Not unity, but what the schoolmen call unicity. De Quincey. [ 1913 Webster ]

The unicity we strive not to express, for that is impossible, but to designate by the nearest analogy. Coleridge. [ 1913 Webster ]