Ignore newly-developed area (6)
I believe the answer is:
region
'area' is the definition.
('region' can be a synonym of 'area')
'ignore newly-developed' is the wordplay.
'newly developed' indicates an anagram.
'ignore' is an anagram of 'REGION'.
(Other definitions for region that I've seen before include "Kind of territory to ignore" , "Area, domain" , "Area, neighbourhood" , "Area - district" , "Part of a country" .)