When the odds offered for a particular race horse are better/longer than what a punter believes they should be.
A punter will take numerous form factors into consideration when deciding which horse to back and if he/she sees value in the price set by the bookies for a certain horse, the odds are considered overs.
For example, if plenty of horse racing tipsters like a horse but the bookies are offering odds of $10, chances are that it is over the odds.
"Have these bookies got their heads screwed on properly? $8 for that horse is way overs."
