Overhead railway and Railroad line

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

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

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