noun
martinet
mar-tin-ET/ˌmɑːrtnˈet/
A person who demands strict discipline and exact obedience.
The martinet demands that the recruit correct even a tiny button misalignment.

Etymology
Martinet was charged with spreading strict drill and discipline through the French infantry. His name first denoted a system of discipline, then a person who insists on exact obedience.
In context
the next minute he was a martinet and driving his men
More examples
- The new manager is a martinet about punctuality.
- Even minor infractions earn a lecture from that martinet.
- The recruits resent the martinets who inspect every button.
Forms
martinet · martinets
Similar words
- disciplinarian
- Enforces discipline without necessarily demanding rigid obedience in every detail.
- taskmaster
- Demands hard work rather than strict obedience to every rule.