The bet before (4)
I believe the answer is:
ante
I believe this clue is a double definition.
'the bet' is the first definition.
(ante is a kind of bet)
'before' is the second definition.
(I've seen this in other clues)
(Other definitions for ante that I've seen before include "Betting stake" , "expected from stake" , "Money for poker" , "A neat sort of prefix" , "Initial bet" .)