Oriental church is newly developed see (7)
I believe the answer is:
chinese
'oriental' is the definition.
(I've seen this before)
'church is newly developed see' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'is newly' becomes 'in' (this could be a standard abbreviation I've not previously seen).
'developed' indicates an anagram.
'see' with letters rearranged gives 'ese'.
'ch'+'in'+'ese'='CHINESE'
Can you help me to learn more?
(Other definitions for chinese that I've seen before include "She nice in this language?" , "Board game, -- checkers" , "- Chequers; - leaves; - puzzle" , "Widely-spoken language" , "Member of Han people" .)