1. a person who acts together with another; a fellow actor or performer
Usage: often used in theater and film contexts
2. a person who participates jointly in an action or undertaking
Usage: formal or legal usage

Examples

• She praised her coactor for his professionalism during the demanding film shoot.
• The two coactors had excellent chemistry on stage.
• He worked closely with his coactor to develop the scene's emotional depth.
• The coactors rehearsed their lines together every morning.
• She and her coactor won awards for their performances in the play.