submanager

/sʌbˈmænɪdʒər/
noun
  1. A person who assists a manager or acts as a manager in a lower or secondary position, often in charge of a specific department or team.
    • The submanager helped train the new employees while the manager was on vacation.
    • The store's submanager handled the inventory orders every week.
    • She was promoted to submanager of the sales team after only six months.