Overhead railway and Railway line

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

Railway line and overhead railway are semantically related. In some cases you can use "Railway line" instead a noun phrase "Overhead railway".

Railway line noun - Line that is the commercial organization responsible for operating a system of transportation for trains that pull passengers or freight.

Overhead railway and railway line are semantically related. Sometimes you can replace phrase "Overhead railway" with "Railway line", this phrases are similar.