Greek character possibly seen as Oriental (7)
I believe the answer is:
chinese
'oriental' is the definition.
(I've seen this before)
'greek character possibly seen' is the wordplay.
'greek character' becomes 'chi' (letter from the Greek alphabet).
'possibly' is an anagram indicator.
'seen' with letters rearranged gives 'nese'.
'chi'+'nese'='CHINESE'
'as' is the link.
(Other definitions for chinese that I've seen before include "Boxes within boxes" , "Oriental language" , "from an Asian country" , "Sinitic" , "Of the most populous country" .)