The Collaborative International Dictionary of English v.0.48:

Endemic \En*de"mic\, Endemical \En*de"mic*al\, a. [Gr. ?, ?; ? +
   ? the people: cf. F. end['e]mique.] (Med.)
   1. Peculiar to a district or particular locality, or class of
      persons; as, an endemic disease.
      [1913 Webster]

   Note: An endemic disease is one which is constantly present
         to a greater or less degree in any place, as
         distinguished from an epidemic disease, which prevails
         widely at some one time, or periodically, and from a
         sporadic disease, of which a few instances occur now
         and then.
         [1913 Webster]

   2. Belonging or native to a particular people or country;
      native as distinguished from introduced or naturalized;
      hence, regularly or ordinarily occurring in a given
      region; local; as, a plant endemic in Australia; -- often
      distinguished from exotic.

            The traditions of folklore . . . form a kind of
            endemic symbolism.                    --F. W. H.
                                                  Myers.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

endemical
    adj 1: of or relating to a disease (or anything resembling a
           disease) constantly present to greater or lesser extent
           in a particular locality; "diseases endemic to the
           tropics"; "endemic malaria"; "food shortages and
           starvation are endemic in certain parts of the world"
           [syn: endemic, endemical] [ant: ecdemic,
           epidemic]