Pronunciation: ' r ō -l ə r- ˌ k ō -st ə r, ' r ō -l ē - ˌ k ō -
Function: noun
Date: 1888
1 : an elevated railway (as in an amusement park) constructed with sharp curves and steep inclines on which cars roll
2 : something resembling a roller coaster especially : behavior, events, or experiences characterized by sudden and extreme changes <an emotional roller coaster >