Bishop right – that is cheese (4)
I believe the answer is:
brie
'cheese' is the definition.
(Brie is an example)
'bishop right that is' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'right' becomes 'r' (common abbreviation).
'that is' becomes 'ie' (abbreviation for id est, 'that is' in Latin).
'b'+'r'+'ie'='BRIE'
(Other definitions for brie that I've seen before include "Kind of soft cheese" , "French produce" , "cheese-producing region" , "Food" , "Bergamot-flavoured tea" .)