Went on horse into the ring for the show (5)
I believe the answer is:
rodeo
'the show' is the definition.
(rodeo is a kind of show)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for rodeo that I've seen before include "American show" , "Horse sporting event for cowboys" , "Wild West contest" , "Horse-riding competition for cowboys" , "Contest of cowboy skills" .)