chthonic

from WordNet (r) 3.0 (2006)

chthonic
    adj 1: dwelling beneath the surface of the earth; "nether
           regions" [syn: {chthonian}, {chthonic}, {nether}]

from The Collaborative International Dictionary of English v.0.48

Chthonic \Chthon"ic\, a. [Gr. ?, ?, the earth.]
   Pertaining to the earth; earthy; as, chthonic religions.
   [1913 Webster]

         [The] chthonic character of the wife of Zeus. --Max
                                                  M["u]ller.
   [1913 Webster] Chthonophagia