Some roulette bets (4)
I believe the answer is:
odds
'some roulette bets' 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 "at this is in dispute" , "Partial darkness" , "The likelihood of something occurring rather than not" , "prices" , "Bookies give them" .)