Bishop, elderly but brave (4)
I believe the answer is:
bold
'brave' is the definition.
(associated in meaning)
'bishop elderly' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'elderly' becomes 'old' (similar in meaning).
'b'+'old'='BOLD'
'but' acts as a link.
(Other definitions for bold that I've seen before include "Like heavy type" , "Conspicuous" , "Prominent" , "sort of face" , "Brave" .)