n.1 a person who directs the performance of an orchestra or choir etc.
2 (fem. conductress) a a person who collects fares in a bus etc. b US an official in charge of a train.
3 Physics a a thing that conducts or transmits heat or electricity, esp. regarded in terms of its capacity to do this (a poor conductor). b lightning-conductor.
4 a guide or leader.
5 a manager or director.
Phrases and idioms:
conductor rail a rail transmitting current to an electric train etc.
Etymology: ME f. F conducteur f. L conductor (as conduct)