Equestrian sport (8)
'equestrian sport' is the definition.
(I know that eventing is a type of equestrian sport)
This is the entire clue.
(Other definitions for eventing that I've seen before include "Equestrian competition" , "Sport consisting of dressage, cross country and show jumping" , "A three-phase equestrian sport" .)
'equestrian sport' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for polo that I've seen before include "Horse-game played with loop" , "Game, anagram of ..." , "Marco" , "Horseback sport" , "Team game played with horses" .)