Female diner rearranged china (6)
I believe the answer is:
friend
'china' is the definition.
(cockney rhyming slang, mate is china plate)
'female diner rearranged' is the wordplay.
'female' becomes 'f' (abbreviation).
'rearranged' is an anagram indicator.
'diner' with letters rearranged gives 'riend'.
'f'+'riend'='FRIEND'
(Other definitions for friend that I've seen before include "China" , "Colleague" , "One in need is one indeed" , "Close associate" , "Buddy, chum" .)