In horse racing, these terms generally describe the perceived ability or potential of a horse:

An inform horse: is a horse that has been performing well recently, meaning it has been consistently winning races or placing highly in races. It is a term used to describe a horse that is currently in good form or shape and has a higher likelihood of continuing to perform well in upcoming races. The horse’s recent performances indicate that it is physically fit, mentally sharp, and has developed good racing habits, which can make it a favourite or contender in races

Exposed: This means the horse has been running in races for a while and its form is well-known. It’s unlikely to surprise anyone with a sudden improvement.

Unexposed: This means the horse is relatively new to racing and hasn’t had many runs. Its true potential is not yet clear and it could potentially surprise people with a good performance.

Promising: This means the horse has shown potential in its races and has given indications that it could perform well in the future.

Progressive: This means the horse has been improving in recent races and is expected to continue improving.

Sleeper: This refers to a horse that has been overlooked or underestimated by the public or bookmakers, but has the potential to perform better than expected. It could be a good value bet.