Fellow meets bishop at vault (4)
I believe the answer is:
tomb
'vault' is the definition.
(I've seen this in another clue)
'fellow meets bishop' is the wordplay.
'fellow' becomes 'tom' (man's name).
'meets' says to put letters next to each other.
'bishop' becomes 'B' (abbreviation for bishop in chess).
'tom'+'b'='TOMB'
'at' acts as a link.
(Other definitions for tomb that I've seen before include "Crypt or grave" , "Burial-vault" , "Place of burial, grave or vault" , "Burial site" , "Building for a body" .)