ଅର୍ଥ : Anything characterized by abrupt and extreme changes (especially up and down).
ଉଦାହରଣ :
The economy has been on a roller coaster all year.
ଅର୍ଥ : Elevated railway in an amusement park (usually with sharp curves and steep inclines).
ସମକକ୍ଷ : big dipper, chute-the-chute