If you marshal people or things, you gather them together and arrange them for a particular purpose.

A marshal is an official who helps to supervise a public event, especially a sports event.

In the United States and some other countries, a marshal is a police officer, often one who is responsible for a particular area.

A marshal is an officer in a fire department.

In Britain and some other countries, a marshal is an officer who has the highest rank in an army or air force.