Rabbit

Also known as a pacemaker; this is a horse with no expected chance of winning but is used to prompt a quick pace on the front end of the race to the benefit of a stablemate who is a closer.

Bolt

A sudden veering to the inside or outside rail, often caused by the horse spooking or shying from something.

Handicap

A race where a handicapper has assigned weights to be carried by all runners on the basis of their past racing efforts.