third rail

1. 1.

   a rail through which electric current is supplied to an electric locomotive

   Broadertrack

Questions about third rail

What does third rail mean?

third rail means "a rail through which electric current is supplied to an electric locomotive".

Is third rail a common word?

third rail is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.