roller_coaster
1. [ noun ] anything characterized by abrupt and extreme changes (especially up and down)
Examples:

"the economy has been on a roller coaster all year"

Related terms: turbulence
2. [ noun ] (transportation,business) elevated railway in an amusement park (usually with sharp curves and steep inclines)
Synonyms: chute-the-chute big_dipper
Related terms: ride el hypercoaster
Similar spelling:   roller-skater
  roller_skate
  roller_skating