campaigner
noun [ C ] uk/ˌkæmˈpeɪ.nər/ us/ˌkæmˈpeɪ.nɚ/
运动参加者;运动倡导者;活动家
a person who takes part in organized activities that are intended to change something in society
an animal rights campaigner 动物权利运动的支持者
She's a campaigner for Friends of the Earth. 她是地球之友运动的参加者。