Island's unnamed lizard detailed by active conservationists (7)
I believe the answer is:
antigua
'island's' is the definition.
(I've seen this before)
'unnamed lizard detailed by active conservationists' is the wordplay.
I cannot really see how this works, but
'active' could be 'a' (grammatical abbreviation) and 'a' is present in the answer.
'conservationists' could be 'nt' (abbreviation for National Trust) and 'nt' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for antigua that I've seen before include "former British possession" , "West Indies island" , "One of the Leeward Islands" , "Aga unit in the West Indies" , "warm island" .)