An actor is a person who acts, or has a role (a part) in a movie, television show, play, or radio show. Actors may be professional or not. Sometimes actors only sing or dance, or sometimes they only work on radio. A woman actor is actress, but the word "actor" is used for both men and women when referring to a group. Actors are also known as ‘thespians’ because of the first known Greek actor ‘Thespis’.