A call made by a bookmaker to the punter for cash to cover some or all of the punters exposure to loss.
A specific type of book offered on an event. For example, a football match
would have many different markets, including match winner, total goals, first goalscorer, most corners, etc.
Multi (Also known as an Accumulator)
A bet in which a single stake is used to generate two or more bets in succession. The punter makes a series of selections each from a different race or event. Every time a selection wins, the stake plus winnings is put onto the next selection. If any selection loses, the whole bet is a loser. (Multis are also known as doubles, trebles, four-folds, five-folds, six-folds, etc, depending on the number of selections.)