Military
- force
A unit that is part of some military service; "he sent Caesar a force of six thousand men...
- army
A permanent organization of the military land forces of a nation or state.
- navy
An organization of military vessels belonging to a country and available for sea warfare.
- air force
The airborne branch of a country's armed forces.
- coastguard
A military service responsible for the safety of maritime traffic in coastal waters.
- Marines
Members of a body of troops trained to serve on land or at sea.