What is a broke horse to ride?

It is a horse that can been ridden...depending on the degree of riding, how much it has been ridden and who it is approved for (i.e. novice, beginner, intermediate or experienced). Such as a green broke horse is a horse that is likely not very well trained yet, and might be started under saddle. A well broke horse, however, has been used under saddle for a while and is likely not to buck anyone off.