People collectively associated with China, mostly (6)
I believe the answer is:
manchu
'people collectively associated with china mostly' is the definition.
I can't judge whether this defines the answer.
'people collectively associated with china mostly' is the wordplay.
'people collectively' becomes 'man'.
'associated with' is a charade indicator (letters next to each other).
'china' becomes 'chum' (china [plate] is Cockney rhyming slang for mate).
'mostly' means to remove the last letter.
'chum' with its final letter removed is 'chu'.
'man'+'chu'='MANCHU'
(Other definitions for manchu that I've seen before include "Seventeenth century conquerors of China" , "Old Chinese" , "Last imperial dynasty of China" , "Chinese dynasty overthrown in 1911" , "old language" .)