Extreme sport, for short

• Big name in stunt bikes
• Sport with stunt riding, informally
• Biker's stunt bike, briefly
• Stunt rider's sport
• Trick bike
• Vehicle to be raced in the Olympics for the first time in 2008
• Stunt biker's bike, briefly

Wikipedia Word definitions in Wikipedia
BMX may refer to: Bicycle motocross , a sport of racing on bicycles on motocross style tracks BMX bike , a bicycle used for casual use and sport, and designed mainly for dirt and motocross cycling Big Mountain Air Force Station (IATA: BMX), a military use ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1978, semi-acronym from bicycle motocross .