role 
/ˈroʊl/ noun
plural roles /ˈroʊl/ noun [count] 1 : the character played by an actor
▪ He plays the role of the villain. ▪ She was given the starring/lead/leading role. ▪ I had a minor/major role in the play. 2 a : a part that someone or something has in a particular activity or situation — usually + in ▪ Everyone had a role [=hand] in winning the game. [=everyone helped to win the game] ▪ The government is taking an active role in improving public schools. [=the government is actively involved in improving public schools] ▪ He had a key role in designing the bridge. ▪ She talked about the roles of exercise and a healthy diet in preventing heart disease. ▪ Newspapers play a major role in determining how people think about politics. ▪ Religion plays an important role in his life. [=religion is very important to him]
b : the part that someone has in a family, society, or other group
▪ After her husband left her, she had to take on the dual role of mother and father for her children. ▪ She likes to play the role of matchmaker with her friends. ▪ She challenged the traditional roles assigned to women. ▪ We'll switch/reverse roles this time, and you can wash the dishes while I dry them. ▪ It was a case of role reversal: the father stayed home with the children while the mother worked.
▪ He plays the role of the villain. ▪ She was given the starring/lead/leading role. ▪ I had a minor/major role in the play.
b : the part that someone has in a family, society, or other group
▪ After her husband left her, she had to take on the dual role of mother and father for her children. ▪ She likes to play the role of matchmaker with her friends. ▪ She challenged the traditional roles assigned to women. ▪ We'll switch/reverse roles this time, and you can wash the dishes while I dry them. ▪ It was a case of role reversal: the father stayed home with the children while the mother worked.
