Leave diamonds for one much admired (3)
I believe the answer is:
god
'one much admired' is the definition.
(gods are worshipped or admired)
'leave diamonds' is the wordplay.
'leave' becomes 'go' (to go is to depart or leave).
'diamonds' becomes 'd' (abbreviation for the card suit diamonds).
'go'+'d'='GOD'
'for' acts as a link.
(Other definitions for god that I've seen before include "Creator of the universe" , "eg Cupid" , "Being upstairs" , "Superhuman being" , "Pan perhaps" .)