{i} supporter of activism, one who advocates active involvement as a means to achieve political or other goals
An activist is a person who works to bring about political or social changes by campaigning in public or working for an organization. The police say they suspect the attack was carried out by animal rights activists. someone who works hard doing practical things to achieve social or political change political/gay/animal rights etc activist
An individual, usually outside of government, who actively promotes a political party, philosophy, or issue he or she cares personally about