n. A person who practices the sport of parkour.
Parkour allows big kids to channel Spiderman with the fearlessness of younger days, balanced with the wisdom of adult discipline and safety. Traceurs range in age from the late teens to early 30s and they typically have some kind of background in gymnastics, martial arts, break dancing or acrobatics. But they can also come in cold, like Sam Wilson, 25, of Mukilteo, who joined a group of experienced traceurs at Freeway Park on Sunday afternoon.
—Athima Chansanchai, “For traceurs, walk in park is no picnic,” Seattle Post-Intelligencer, December 19, 2005
"The point is overcoming any obstacle," 18-year-old Ryan Ford tells a circle of young guys around him.

As if to explain, he takes position atop a 10-foot wall enclosing a sculpture park in downtown Denver. With a running start, Ford lunges hands-first at a railing, vaulting himself backwards over the wall and deftly landing on the ground.

Not missing a beat, he springs forward, bounding over a concrete block and soaring 6 feet into the air, landing on the ledge of a wall, gripping it with the tips of his fingers and toes in what is known as — most appropriately — a cat leap.

Ford is a traceur. And he's practicing what's known in the French world as Parkour, or in English parlance, freerunning.
—Megan McCloskey, “Going with the flow; Leaping objects in a single bound is just a way of life for traceurs,” Associated Press, November 16, 2005
2003 (earliest)
Parkour competitors are called traceurs, and they do "runs" across rooftops, down staircases, over railings in a stylish and acrobatic way. Traceurs often form "clans," or groups, to practice their runs.
—Steve Goldstein, “Blue Skies?,” The Philadelphia Inquirer, July 13, 2003