What is the meaning of role?

noun

• The actions and activities assigned to or required or expected of a person or group.
  • usage: "the function of a teacher"; "the government must do its part"; "play its role"
  • synonyms: function, office, part
• An actor's portrayal of someone in a play.
  • usage: "she played the part of Desdemona"
  • synonyms: character, theatrical role, part, persona
• What something is used for.
  • usage: "the function of an auger is to bore holes"; "ballet is beautiful but what use is it"
  • synonyms: function, purpose, use
• Normal or customary activity of a person in a particular social setting.
  • usage: "what is your role on the team"