Four-legged reptile (6)
I believe the answer is:
lizard
'four-legged reptile' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for lizard that I've seen before include "Gecko, for example" , "The most Southerly point of England" , "leading to a windswept village" , "Reptile with two pairs of legs" , "Type of reptile" .)