National Guard
noun
state military forces, in part equipped, trained, and quartered by the U.S. government, and paid by the U.S. government, that become an active component of the army when called into federal service by the president in civil emergencies.
Compare militia(def 2).
British Dictionary definitions for national guard
National Guard
noun
(sometimes not capitals)
the armed force, first commanded by Lafayette, that was established in France in 1789 and existed intermittently until 1871
(in the US) a state military force that can be called into federal service by the president
Cultural definitions for national guard
National Guard
The volunteer military forces of each state, which the governor of a state can summon in times of civil disorder or natural disaster. Through congressional and presidential order, the National Guard can be called into service in the regular United States army.