demote (verb)

1. In the movie, the CEO decided to demote the hardworking employee to a lower position due to a mistake.

2. The art teacher had to demote the student's grade after discovering that they had plagiarized their artwork.

3. After her boyfriend lied to her, she made the difficult decision to demote him from being her partner to just a friend.

4. In the novel, the protagonist's betrayal led his best friend to demote their friendship to a mere acquaintance.