slacklining

slacklining
 n.— «We were at the University of Minnesota, where a burgeoning sport called slacklining was being practiced between tall oak trees on the grassy mall in front of Northrop Auditorium. Like its cousin sport of tightrope walking, slacklining requires focus and acute balance to walk thin pathways through the air.» —“Ultrafit: One with the webbing” by Stephen Regenold Star Tribune (Minneapolis-St. Paul, Minnesota) Sept. 12, 2007. (source: Double-Tongued Dictionary)