Big air is a sports discipline where the competitor rides a vehicle (such as a snowboard, a skateboard, a ski or a motocross motorcycle) down a hill and perform tricks after launching off very large jumps. It is an extreme version of slopestyle. Competitors perform complex tricks in the air, aiming to attain sizable height and distance as well, all while securing a clean landing. Many competitions also require the rider to do a specific trick to win the major prize.
Since 2003 Big air is featured in FIS Snowboard World Championships.
References
Big air Wikipedia(Text) CC BY-SA