Meaning : Anything characterized by abrupt and extreme changes (especially up and down).
Example :
The economy has been on a roller coaster all year.
Meaning : Elevated railway in an amusement park (usually with sharp curves and steep inclines).
Synonyms : big dipper, chute-the-chute
Roller coaster ka meaning, vilom shabd, paryayvachi aur samanarthi shabd in Marathi. Roller coaster ka matlab kya hota hai?