(In a rodeo) an untrained (or part-trained) horse or bronc ridden with a saddle; the action or practice of riding such a horse; frequently attributive.
Origin
1930s.
Definition of saddle bronc in US English:
saddle bronc
noun
US
(In a rodeo) an untrained (or part-trained) horse or bronc ridden with a saddle; the action or practice of riding such a horse; frequently attributive.