caudal fin

English Thesaurus

1. the tail of fishes and some other aquatic vertebrates (noun.animal)

hypernym	:	fin,
definition	:	organ of locomotion and balance in fishes and some other aquatic animals (noun.animal)

hyponym	:	heterocercal fin,
definition	:	a tail fin with unequal lobes in which the vertebral column turns upward into the larger lobe as in sharks (noun.animal)

hyponym	:	homocercal fin,
definition	:	symmetrical tail fin extending beyond the end of the vertebral column as in most bony fishes (noun.animal)

part meronym	:	fish,
definition	:	any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills (noun.animal)