Definitions of noumena on the Web:

• (Gr.) The true essential nature of Being as distinguished from the illusive objects of sense.
  www.theosociety.org/pasadena/key/key-glo3.htm
• From the Greek, "thing in itself," in contrast with the idea of phenomena (or phenomenal realm) , as exposited in the thought of Immanuel Kant (1724-1804). Noumena, or the noumenal realm have to do with those aspects of reality which cannot be experienced through the senses (eg the spiritual world). ...
  www.apologetics.org/glossary.html

Definitions of phenomena on the Web:

• A phenomenon (plural: phenomena) is an observable event, especially something special (literally something that can be seen from the Greek word phainomenon = observable).
  en.wikipedia.org/wiki/Phenomena
• that which appears to the senses.
  www.willdurant.com/glossary.htm
• In the thought of Kant, the phenomenal realm is the world of matter - ie the world which we can experience through our senses. It is thus distinguished with the noumenal realm. see noumena, noumenal realm.
  www.apologetics.org/glossary.html