Tailless amphibian (4)
I believe the answer is:
frog
'tailless amphibian' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for frog that I've seen before include "Leaping amphibian" , "throat problem" , "Long-legged amphibian" , "Amphibious neighbour of 12?" , "Grown-up tadpole" .)