switchback vs zig

switchback

noun
  • A sharp bend in a path or road which causes a traveller to almost reverse their direction of travel, especially one of a series of such bends on an incline; a hairpin bend; also a path or road having such a series of bends. 

  • A railway track on a steep slope in a zigzag formation, in which a train travels in a reverse direction at each switch. 

  • A railway track on which there are steep ascents and descents, a train moving partially or fully by the force of gravity using the momentum generated when descending to travel up an ascending part of the track; especially (Britain, dated), such a track built for fun rides at an amusement park; a type of rollercoaster. 

  • A flight path consisting of a series of steep ascents and descents, generally flown as a stunt. 

  • A path or road having a series of steep ascents and descents. 

verb
  • To take a zigzag course or path. 

zig

noun
  • A sudden or sharp turn or change of direction. 

verb
  • To make such a turn. 

How often have the words switchback and zig occurred in a corpus of books? (source: Google Ngram Viewer )