roller-coaster

verb (used without object)

1. to go up and down like a roller coaster; rise and fall: a narrow road roller-coastering around the mountain; a light boat roller-coastering over the waves.
2. to experience a period of prosperity, happiness, security, or the like, followed by a contrasting period of economic depression, despair, or the like: The economy was roller-coastering throughout most of the decade.

adjective

3. of, relating to, or characteristic of a roller coaster.
4. resembling the progress of a ride on a roller coaster in sudden extreme changeableness.

noun

1. a small gravity railroad, especially in an amusement park, having a train with open cars that moves along a high, sharply winding trestle built with steep inclines that produce sudden, speedy plunges for thrill-seeking passengers.
2. a car or train of cars for such a railroad.
3. any phenomenon, period, or experience of persistent or violent ups and downs, as one fluctuating between prosperity and recession or elation and despair.

noun

1. another term for big dipper