The Collaborative International Dictionary of English v.0.48:

caecum \cae"cum\, n.; pl. C[ae]cums, L. C[ae]ca. [L. caecus
   blind, invisible, concealed.] (Anat.)
   (a) A cavity open at one end, as the blind end of a canal or
       duct.
   (b) The blind part of the large intestine beyond the entrance
       of the small intestine; -- called also the blind gut.
       [Also spelled cecum.]
       [1913 Webster]

   Note: The c[ae]cum is comparatively small in man, and ends in
         a slender portion, the vermiform appendix; but in
         herbivorous mammals it is often as large as the rest of
         the large intestine. In fishes there are often numerous
         intestinal c[ae]ca.
         [1913 Webster]

WordNet (r) 3.0 (2006):

caecum
    n 1: the cavity in which the large intestine begins and into
         which the ileum opens; "the appendix is an offshoot of the
         cecum" [syn: cecum, caecum, blind gut]