collaborator
Definitions
A person who works jointly on an activity or project.
A person who cooperates traitorously with an enemy that has occupied their country.
Examples
The lead researcher thanked every collaborator for their invaluable contributions to the project.
He was accused of being a collaborator with the enemy during the occupation.
As a frequent collaborator with local artists, she has helped revitalize the city's creative scene.
Synonyms
partner ally teammate associate colleague cooperator accomplice