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.

Underlay

A horse that is going off at lower odds than it deserves based on performance.

Dead Heat

Two or more horses finishing so close at the wire, that they were unable to be separated on a photo finish and deemed to have tied.