Definition of "noumenal"

noumenal

adjective
not comparable
1. (philosophy, especially Kantianism) Of or pertaining to the noumenon or the realm of things as they are in themselves.
  Quotations
  We may here distinguish between two kinds of reality, phenomenal or relative, and noumenal or absolute.
  1878, James Sully, “The Question of Visual Perception in Germany”, in Mind, volume 3, number 10, page 193
  When Kant says that it is impossible to know anything about, or apply any categories to, the noumenal realm, he would seem to be doing just what cannot be done.
  2003, Jay Garfield, Graham Priest, “Nāgārjuna and the Limits of Thought”, in Philosophy East and West, volume 53, number 1, page 3