Bishop, he turned up to lead ancient see (6)
I believe the answer is:
behold
'see' is the definition.
(beholding is a kind of seeing)
'bishop he turned up to lead ancient' is the wordplay.
'bishop' becomes 'B' (abbreviation for bishop in chess).
'turned up' says the letters should be written in reverse.
'to lead' is a charade indicator (letters next to each other).
'ancient' becomes 'old' (similar in meaning).
'he' backwards is 'eh'.
'b'+'eh'+'old'='BEHOLD'
(Other definitions for behold that I've seen before include "See, with attention" , "Archaic word for see or observe" , "Look at with attention" , "Lo - look!" , "Archaic injunction to observe" .)