The Collaborative International Dictionary of English v.0.48:

Caudal \Cau"dal\, a. [L. Cauda tail. Cf. Coward.]
   Of the nature of, or pertaining to, a tail; having a
   tail-like appendage.
   [1913 Webster]

         The male widow-bird, remarkable for his caudal plumes.
                                                  --Darwin.
   [1913 Webster]

   Caudal fin (Zool.), the terminal fin (or "tail") of a fish.
      [1913 Webster]

WordNet (r) 3.0 (2006):

caudal
    adv 1: toward the posterior end of the body [syn: caudally,
           caudal]
    adj 1: constituting or relating to a tail; "caudal appendage"
           [ant: cephalic]
    2: resembling a tail [syn: caudal, taillike]
    3: situated in or directed toward the part of the body from
       which the tail arises; "caudal fins"; "the caudal end of the
       body"

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "caudal":
   boundary, caudate, caudated, caudiform, conclusive, definitive,
   determinative, endmost, eventual, extreme, farthest, final, last,
   limiting, polar, tail, tailed, taillike, terminal, terminating,
   terminative, ultimate