What is Conductor ?
Conductor is (noun) 1. a metal, or other substance through which heat or electricity can pass Copper is a good conductor but plastic is not. 2. the person who directs an orchestra As the orchestra reached the grand finale, the conductor started to sing. The conductor asked the horns to play more softly. 3. US a person in charge of a train (NOTE: The British term is railway guard.)
source: Easier English, Student Dictionary Upper Intermediate Level