roller coaster

Từ điển WordNet v3.1 - WordNet Dictionary

noun

1. anything characterized by abrupt and extreme changes (especially up and down)
- the economy has been on a roller coaster all year
• Hypernyms:
turbulence, upheaval, Sturm und Drang
2. elevated railway in an amusement park (usually with sharp curves and steep inclines)
• Syn:
big dipper, chute-the-chute
• Hypernyms:
elevated railway, elevated railroad, elevated, el, overhead railway, ride
• Hyponyms:
hypercoaster