Source : Webster's Revised Unabridged Dictionary (1913)

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

         The male widow-bird, remarkable for his caudal plumes.
                                                  --Darwin.

   {Caudal fin} (Zo["o]l.), the terminal fin (or ``tail'') of a
      fish.

Source : WordNet®

caudal fin
     n : the tail of fishes and some other aquatic vertebrates [syn:
         {tail fin}]