1 a track at a fairground or amusement park that goes up and down very steep slopes and which people ride on in small carriages for fun and excitement: The girls wanted to have a go on the roller coaster.
az: attraksion
ru: американские горки
2 a situation in which there are often big and sudden changes: an emotional rollercoaster.
az: ani dəyişiklik
ru: резкий перепад, мгновенное измение