Source : Webster's Revised Unabridged Dictionary (1913)

Hypochondrium \Hy`po*chon"dri*um\, n.; pl. L. {Hypochondria}, E.
   {Hypochondriums}. [L., fr. Gr. ?, from ? under the cartilage
   of the breastbone; ? under + ? cartilage.] (Anat.)
   Either of the hypochondriac regions.

Source : WordNet®

hypochondrium
     n : the upper region of the abdomen just below the lowest ribs
         on either side of the epigastrium
     [also: {hypochondria} (pl)]