Bullet (work)
The best workout time for a particular distance on a given day at a track. From the printer's "bullet" that precedes the time of the workout in listings. Also known as a "black-letter" work in some parts of the country.  

Bullring
A small racetrack, usually less than one mile.  

Bute
Short for phenylbutazone, a non-steroidal anti-inflammatory medication that is legal in many racing jurisdictions. Often known by the trade names Butazolidin and Butazone.  

Buy Back
A horse put through a public auction that did not reach a minimum (reserve) price set by the consignor and so was retained. The consignor must pay a fee to the auction company based on a percentage of the reserve, to cover the auction company's marketing, advertising and other costs.