The Collaborative International Dictionary of English v.0.48:

Endemic \En*dem"ic\, n. (Med.)
   An endemic disease.
   [1913 Webster]

         Fear, which is an endemic latent in every human heart,
         sometimes rises into an epidemic.        --J. B. Heard.
   [1913 Webster]

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):

endemic
    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]
    2: native to or confined to a certain region; "the islands have
       a number of interesting endemic species" [ant:
       cosmopolitan, widely distributed]
    3: originating where it is found; "the autochthonal fauna of
       Australia includes the kangaroo"; "autochthonous rocks and
       people and folktales"; "endemic folkways"; "the Ainu are
       indigenous to the northernmost islands of Japan" [syn:
       autochthonal, autochthonic, autochthonous, endemic,
       indigenous]
    n 1: a disease that is constantly present to a greater or lesser
         degree in people of a certain class or in people living in
         a particular location [syn: endemic, endemic disease]
    2: a plant that is native to a certain limited area; "it is an
       endemic found only this island"

Moby Thesaurus II by Grady Ward, 1.0:

99 Moby Thesaurus words for "endemic":
   abnormality, aboriginal, acute disease, affection, affliction,
   ailment, allergic disease, allergy, atrophy, autochthonous,
   bacterial disease, birth defect, blight, cardiovascular disease,
   catching, chronic disease, circulatory disease, communicable,
   complaint, complication, condition, congenital defect, contagious,
   defect, deficiency disease, deformity, degenerative disease,
   disability, disease, disorder, distemper, endemic disease,
   endocrine disease, epidemial, epidemic, epidemic disease,
   epiphytotic, epizootic, functional disease, fungus disease,
   gastrointestinal disease, genetic disease, handicap,
   hereditary disease, homebred, homegrown, iatrogenic disease,
   illness, indigenous, indisposition, infectious, infectious disease,
   infective, infirmity, inoculable, malady, malaise, morbidity,
   morbus, muscular disease, natal, native, native-born,
   neurological disease, nutritional disease, occupational disease,
   organic disease, original, pandemic, pandemic disease,
   pathological condition, pathology, pestiferous, pestilential,
   plant disease, primitive, protozoan disease, psychosomatic disease,
   respiratory disease, rockiness, secondary disease, seediness,
   sickishness, sickness, signs, sporadic, spreading, symptomatology,
   symptomology, symptoms, syndrome, taking, the pip,
   urogenital disease, vernacular, virus disease, wasting disease,
   worm disease, zymotic