黒帯

1. Origins, structure, and basic meaning

• Structure: 黒帯（くろおび） means a black belt or a martial artist who holds that rank.
• Basic usage: Use it for earning a black belt through training or for an advanced practitioner teaching beginners.

2. Common pitfalls and similar expressions

• The belt and the person holding it
  • 黒帯を取る means earning a black belt.
  • In 道場の黒帯が教える, the teacher is the person holding the black belt, not the belt itself.