demote (one) to (something)

To reassign one to a role or position with less authority or responsibility. I'm worried that if the boss finds out this blunder was my fault, she'll demote me to a lower position. Raise your voice to me again, Detective, and I'll demote you to traffic cop! A: "I thought Bill had a prominent role on the steering committee." B: "He did, but the headmaster demoted him to minute taker, and I have no idea why."