activist
n. countable C1 Advanced Oxford US //ˈæktəvəst// UK //ˈæktɪvˌɪst// ac·tivist
n. a person who works hard to bring about social or political change. You often see them organizing protests or campaigns for causes they believe in.
n. a person who campaigns to bring about political or social change. Often used in conjunction with a specific cause or ideology.
The environmental activist spoke at the local rally.
After years of working as a community activist, she finally saw the city council pass the new housing law.
While some critics dismissed the movement as performative, the lead activist maintained that consistent public pressure was the only way to force a legislative response.
From active + -ist.
Usage
Commonly modified by an adjective or noun phrase specifying the cause, such as 'human rights' or 'climate'.