番犬

1. Origins, structure, and basic meaning

• Structure: The spelling is 番犬, read as ばんけん. It is a noun for a dog kept to guard a home, warehouse, or property and alert people to unfamiliar intruders.
• Basic usage: A guard dog watching an entrance appears in 番犬が入口を守る, while a guard dog barking low at unfamiliar footsteps appears in 番犬が低くほえる.

2. Common pitfalls and similar expressions

• Difference from 飼い犬
  • It is not simply any domesticated dog but one assigned the specific role of guarding and protection.