Definitions for "ODDS-ON"
Keywords:  stake, outlay, bookmaker, horse, win
If a horse is very likely to win, the odds may be shorter than evens, for example, 4/5 - which means that the bookie thinks the horse is more likely to win than not to win by a ratio of 5 to 4. Such odds are expressed as 8/11, and pronounced as 11 to 8 on). What it means in practice is that you have to stake more than you will win - so, for example, odds of 8/11 mean you will win £8 for every £11 staked - and get a return of £19.
A bet where you have to stake more than the amount you expect to profit by.
having a better than even chance of success; "the odds-on favorite"