Sentence examples for black belt from inspiring English sources

The phrase "black belt" is correct and can be used in written English.
It is commonly used to refer to a person who has achieved a high level of expertise or mastery in a certain skill or activity, particularly in martial arts. For example: - He has been training for years and is now a black belt in taekwondo. - The company is looking for a black belt in project management to lead the team. - After years of practice, she finally earned her black belt in karate.