An undercover person is someone who works or acts secretly to achieve their goals.
You might have seen movies or TV shows about detectives or agents going undercover - they disguise themselves as something else and try to blend in with a group of people, usually for a specific reason. It could be to catch a bad guy, solve a crime, or gather information. In real life, people who work in security or law enforcement might go undercover too, like an FBI agent pretending to be a new employee at a company that's suspected of being involved in something shady. The idea is for the person to become so well integrated into the group they're investigating that others don't even suspect them of being anything other than one of their own.
A person who works undercover.
To provide too little coverage.
Performed or happening in secret.
