Meaning : (usually plural) the office that serves as the administrative center of an enterprise.
Example :
Many companies have their headquarters in New York.
Synonyms : central office, home base, home office, main office
Meaning : The military installation from which a commander performs the functions of command.
Example :
The general's headquarters were a couple of large tents.
Synonyms : hq, military headquarters
Meaning : (plural) a military unit consisting of a commander and the headquarters staff.