noun
electoral district; precinct
Refers to a geographical area represented by an elected official. Used in political and administrative contexts.
次の選挙から選挙区の区割りが変わる。
The electoral district boundaries will change from the next election.
彼は地元の選挙区で圧倒的な支持を得ている。
He has overwhelming support in his local electoral district.
区 is a generic term for 'ward' or 'district', whereas 選挙区 is specifically an electoral district.
Compound of 選挙 (senkyo, 'election') and 区 (ku, 'district'). The term is a straightforward modern formation for 'electoral district'.