/æksɛˈsɔːriəl/ – Noun
Definition: 1. tòng phạm, đồng phạm;
2. phụ tùng, phụ liệu.
A more thorough explanation: A person who aids or assists in the commission of a crime, but who is not directly involved in the act itself.
Example: John was found guilty of being an accessorial to the robbery, as he provided the getaway car.