What is Agent Provocateur?

Legal Definition
An agent provocateur (French for "inciting agent") is a person who commits, or who acts to entice another person to commit an illegal or rash act or falsely implicate them in partaking in an illegal act. An agent provocateur may be acting out of their own sense of duty or may be employed by the police or other entity to discredit or harm another group (such as a peaceful protest or demonstration) by provoking them to commit a crime, thereby undermining the protest or demonstration as a whole.

In accordance with French grammar, the plural form of the term is, agents provocateurs; a female agent is an agente provocatrice.

To prevent infiltration by agents provocateurs, the organizers of large or controversial assemblies may deploy and coordinate demonstration marshals, also called stewards.
-- Wikipedia
Legal Definition
When one party convinces another to commit a crime getting that person arrested as well. Similar to accomplice.