Source : Webster's Revised Unabridged Dictionary (1913)

Fundus \Fun"dus\, n. [L., bottom.] (Anat.)
   The bottom or base of any hollow organ; as, the fundus of the
   bladder; the fundus of the eye.

Source : WordNet®

fundus
     n : (anatomy) the base of a hollow organ or that part farthest
         from its opening; "the uterine fundus"
     [also: {fundi} (pl)]