A person who acts a part in a theatrical play or (later) in film or television; a dramatic performer.
Someone or something that takes part in some action; a doer, an agent.
The entity that performs a role (in use case analysis).
The subject performing the action of a verb.
A person who entertains others, esp. as a profession, as a singer, actor, presenter, dancer, musician, magician, comedian, etc.
Someone who puts on a show for the entertainment or enjoyment of others.