Chameleon (6)
I believe the answer is:
lizard
'chameleon' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for lizard that I've seen before include "Kind of reptile - chameleon is one" , "See 1 Across" , "Reptile such as skink" , "Four-legged reptile" , "Type of reptile" .)