noun / adjective
deputy
DEP-yoo-tee/ˈdepjuti/
A person authorized to act for a superior.
The deputy chairperson leads the meeting with the chairperson's approval.

Etymology
Deputé names a person who has been appointed or assigned. This explains why a deputy can exercise another official's powers without personally holding that office.
In context
a deputy, an official who holds genuine power over a genuine domain, but who answers to a higher desk somewhere else.
More examples
- The director's deputy signs the report in her absence.
- The sheriff sends two deputies to investigate the complaint.
- As deputy manager, Lena handles decisions when the manager is away.
Forms
deputy · deputies
deputize verb — To authorize someone to act as a deputy.
Similar words
- representative
- May act for a group rather than a superior.
- delegate
- Receives authority for specific tasks, not necessarily a superior's role.
- substitute
- Takes another person's place without necessarily receiving official authority.