• 区役所くやくしょ — ward office
• 地区ちく — local area, district
• 区分くぶん — classification, division
• 区画くかく — block, lot, section
• 学区がっく — school district
• 市区町村しくちょうそん — city, ward, town, and village (municipalities)

区 is derived from components meaning “to enclose” and “many items,” expressing the idea of separating or dividing space. It's used to denote sections within cities or organizations.