Definition of "frontside"

His routine, as described by the Canadian Snowboard Federation, sounded like a day on the golf course: it featured a "front nine, a back nine, a front five followed by frontside and backside air, ending with a back ten to impress the judges and large crowd.

2009 January 24, Randy Starkman, “Silver medal eases pain for Batchelor at world championships”, in Toronto Star‎