noun (n)

• (usually plural) the office that serves as the administrative center of an enterprise(noun.artifact)

  Example:
  Many companies have their headquarters in New York.
  

  Synonym:
  central office, home base, home office, main office
  

  source: wordnet30
• the military installation from which a commander performs the functions of command(noun.artifact)

  Example:
  The general's headquarters were a couple of large tents.
  

  Synonym:
  hq, military headquarters
  

  source: wordnet30
• (plural) a military unit consisting of a commander and the headquarters staff(noun.group)

  source: wordnet30
• The quarters or place of residence of any chief officer, as the general in command of an army, or the head of a police force; the place from which orders or instructions are issued; hence, the center of authority or order.(noun)

  source: webster1913