the person who leads a musical group
"The conductor raised his baton, signaling the orchestra to begin their performance."
a substance that readily conducts e.g. electricity and heat
"Copper is an excellent conductor used in wiring to efficiently transmit electrical current throughout the house."
the person who collects fares on a public conveyance
"The bus conductor collected my fare and gave me back the correct change."
a device designed to transmit electricity, heat, etc.
"The metal rod acted as an effective conductor, quickly transferring heat from the stove to the pot."
One who conducts or leads; a guide; a director.
"The experienced conductor guided the lost hikers safely back to their campsite."
In plain English: A conductor is someone who leads an orchestra by using hand gestures to control when musicians play and how loud they sound.
"The conductor announced that this is our final stop before reaching downtown."
Usage: In musical contexts, this term refers specifically to the leader of an orchestra or choir rather than someone who simply plays an instrument. It is often confused with "manager," but while a manager handles business affairs, a conductor directs the performance itself.
The word comes from the Latin conductor, which originally meant someone who hires out or manages property. It entered English through Middle French and Old French as conductour.