rollercoaster
Pronunciation:
/ˈɹoʊlɚˌkoʊstɚ/noun
Definitions
An amusement ride consisting of a buggy on a track that rises, falls, twists and turns.
(by extension) Any situation in which there are ups and downs, or violent changes.
Example: Our relationship was quite a rollercoaster. Finally, I had enough of it and left her.