From Longman Dictionary of Contemporary Englishthree-day eventˌthree-day eˈvent noun [countable] DSH British English a horse-riding competition that takes place for three days
Examples from the Corpus
three-day event• Princess Anne herself is a former three-day event world champion and competed at the l976 Montreal Olympics.• Equestrian: The endurance phase of the individual three-day event takes over.• Equestrian: Kerry Millikin on Out and About is in third place heading into the jumping phase of the individual three-day event.• The other disciplines are dressage and the three-day event.• They arrested eighty people after a tip-off that the three-day event was to take place.• An estate sale will continue throughout the three-day event.• The three-day event is for the trade, but the exhibits will be on view to the public beginning March 18. 