'main office' definitions:

Definition of 'main office'

(from WordNet)
noun
(usually plural) the office that serves as the administrative center of an enterprise; "many companies have their headquarters in New York" [syn: headquarters, central office, main office, home office, home base]

Definition of 'main office'

From: GCIDE
  • main office \main office\ n. The office that serves as the administrative center of an enterprise,
  • Syn: headquarters, central office, home office. [WordNet 1.5]

Synonyms of 'main office'

From: Moby Thesaurus