noun
operative
AH-puh-ruh-tiv/ˈɑːpərətɪv/
A person who works secretly for an organization.
The operative discreetly watches a meeting from a distance.

Etymology
The adjective meant ‘active’ or ‘working’ before becoming a noun for a worker or operator. Its secret-agent meaning probably arose through use as a title for private detectives.
In context
The operative who placed the Gerard DeLeon suitcase in April 1943 survived returned to resistance work.
More examples
- Several operatives gathered information for the organization.
- The agency withdrew its operative after the leak.
- She played an undercover operative in the film.
Forms
operative · operatives
Similar words
- agent
- A broader representative role, which need not be secret.
- spy
- Spy specifically gathers secret information rather than performing any covert assignment.