Track and Underground railway

Track noun - A mark or series of marks left on a surface by something that has passed along it.

Underground railway and track are semantically related. In some cases you can use "Underground railway" instead a noun "Track".

Nearby Words: trace, tracing, tracked, tracking, tracker

Underground railway noun - Secret aid to escaping slaves that was provided by abolitionists in the years before the American Civil War.

Track and underground railway are semantically related. Sometimes you can use "Track" instead a noun phrase "Underground railway".