Gambler's concern (4)
'gambler's concern' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for odds that I've seen before include "They could be evens" , "Chances, probability" , "Estimate of likelihood" , "Betting rates" , "Take chances" .)
(Other definitions for ante that I've seen before include "Each player's initial contribution to the pot" , "expected from stake" , "'Behind, before (4)'" , "Player's stake in poker - a ten? (anag)" , "Prefix meaning before" .)
(Other definitions for bad luck that I've seen before include "Misfortune" , "What's brought by 1 across" , "Unnecessary and unforeseen trouble" , "Hard cheese" , "Hard lines!" .)