Big dipper and Overhead railway

Big dipper noun - Elevated railway in an amusement park (usually with sharp curves and steep inclines).

Overhead railway and big dipper are semantically related. In some cases you can use "Overhead railway" instead a noun phrase "Big dipper".

Overhead railway noun - A railway that is powered by electricity and that runs on a track that is raised above the street level.

Big dipper and overhead railway are semantically related. Sometimes you can replace phrase "Big dipper" with "Overhead railway", this phrases are similar.