郡

1. Origins, structure, and basic meaning

• Structure: 郡, read ぐん, refers to a district used to divide a region.
• Basic usage: It is used to discuss boundaries on old maps or the former divisions of a region.
  • 昔の地図には郡の境界が赤い線で示されている。

2. Common pitfalls and similar expressions

• Homophone 軍
  • 郡 and 軍 are both read ぐん, but 郡 is a territorial division and 軍 means an army or military force. Distinguish contexts about maps and boundaries from those about military organizations.