A person who gives police information about crimes and offenders.
Example sentencesExamples
I enclose a summary of his paid activities as a police informer.
Those orders are perfectly normal orders to protect the names of police informers and persons of a similar kind.
And he confessed that he'd been involved in the murder of this individual, who was apparently a police informer of some sort.
The applicants compare the situation to that of the police informers.
Rather than protest or opposition, this discontent gave rise to a sense of apathy and resignation, a situation that was vividly described in the report of a police informer in January 1939.