The Oxford Thesaurus An A-Z Dictionary of Synonyms - regionn.

1) district, area, zone, territory, division, locality, sector, section, tract, part, dominion, precinct, province, quarter, department: Each region is under the suzerainty of a powerful dictator. 2) sphere, territory, domain, province, field, ambit, pale, jurisdiction, bailiwick: She is an expert in the region of climatology.