noun
commander
kuh-MAN-der/kəˈmændər/
A person invested with authority to lead a force.
The commander orders the troops to return to their base.

Etymology
A commander is literally someone who gives orders with authority. The military sense applies that general role to a person empowered to direct troops or operations.
In context
When I first came to Afghanistan in 2005 as a foreign minister, I met the commander of ISAF, the international troops.
As the highest military commander of the Netherlands, with troops stationed around the world, I'm really honored to be here today.
More examples
- The commanders meet to coordinate their units' movements.
- Firefighters wait for instructions from the incident commander.
- The ship's commander changes course to avoid the storm.
Forms
commander · commanders
command verb — To direct others with official authority.