Eager for silver turnover (4)
I believe the answer is:
agog
'eager' is the definition.
(I've seen this before)
'silver turn-over' is the wordplay.
'silver' becomes 'Ag' (Ag is the chemical symbol for silver).
'turn' becomes 'go' (a person's move in a board game).
'over' is a reversal indicator.
'go' reversed gives 'og'.
'ag'+'og'='AGOG'
'for' acts as a link.
(Other definitions for agog that I've seen before include "Very eager (in anticipation)" , "On tenterhooks" , "Open-mouthed" , "Full of excitement" , "State of wide-eyed wonder" .)