switchback

 
Pronunciation: /ˈswɪtʃbak/

noun

  • 1British a road, path, or railway with alternate sharp ascents and descents: the path was a switchback of hills and wooded dales [as modifier]: it is a switchback journey with many ups and downs
  • a roller coaster.
  • 2North American a 180° bend in a road or path, especially one leading up the side of a mountain: the trail soon leads robustly straight up, with few switchbacks [as modifier]: a switchback road