The Collaborative International Dictionary of English v.0.48:

Corium \Co"ri*um\ (k?"r?-?m), n. [L. corium leather.]
   1. Armor made of leather, particularly that used by the
      Romans; used also by Enlish soldiers till the reign of
      Edward I. --Fosbroke.
      [1913 Webster]

   2. (Anat.)
      (a) Same as Dermis.
      (b) The deep layer of mucous membranes beneath the
          epithelium.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dermis \Der"mis\, n. [NL. See Derm.] (Anat.)
   The deep sensitive layer of the skin beneath the scarfskin or
   epidermis; -- called also true skin, derm, derma,
   corium, cutis, and enderon. See Skin, and Illust. in
   Appendix.
   [1913 Webster]

WordNet (r) 3.0 (2006):

corium
    n 1: the deep vascular inner layer of the skin [syn: dermis,
         corium, derma]