Playwright unknown in China? (7)
I believe the answer is:
pottery
'china?' is the definition.
(thesaurus)
'playwright unknown' is the wordplay.
'playwright' becomes 'Potter' (playwright Dennis Potter).
'unknown' becomes 'y' (algebra).
'potter'+'y'='POTTERY'
'in' acts as a link.
(Other definitions for pottery that I've seen before include "Goods of fired clay" , "Items made from clay" , "Ceramics factory" , "baked goods" , "Items of fired clay" .)