Tack
The equipment the horse wears, including saddle and bridle. A jockey typically has their own racing saddle, placed on each horse they ride just before the race.
Bobble/Stumble
A slip or a duck from a horse trying to leave the starting gates, often caused by the surface giving way under the feet. This can range from a mild misstep to a stumble down to their knees.
Objection
Claim of foul lodged by a jockey for perceived dangerous or illegal riding by a rival.

