a center of operations, as of the police or a business, from which orders are issued; the chief administrative office of an organization

The operatives were always in touch with headquarters.

the offices or working location of a military commander; the place from which a commander customarily issues orders.

a military unit consisting of the commander, his staff, and other assistants.

noun

base , base of operations , central station , command post , company headquaters , high command , hq , main office , nerve center , complex , station , focus , heart , hub , seat , center , command , depot , operations , post , precinct