A leader.
One who conducts or leads; a guide; a director.
A person who conducts an orchestra, choir or other music ensemble; a professional whose occupation is conducting.
An ideal of a ring that measures how far it is from being integrally closed
A grooved sound or staff used for directing instruments, such as lithontriptic forceps; a director.
A person who takes tickets on public transportation and also helps passengers.
Something that can transmit electricity, heat, light, or sound.
In certain nations the highest military rank, ranking below only the commander in chief; now essentially disused.