Activism, in a general sense, can be described as involvement in action to bring about change, be it social, political, environmental, or other change. This action is in support of or opposition to one side of a controversial argument.
There are many different forms of activism; a select list follows.
... was a professor and lecturer at Yale University (one of his students was Thornton Wilder) who began acting on Broadway in 1936.
He was typecast as the wasp-tongued, ...