protester
US /ˈproʊ.tes.tɚ/
UK /ˈproʊ.tes.tɚ/

1.
Demonstrant, Protestierender
a person who publicly demonstrates strong objection to something or expresses dissent, often as part of a group
:
•
The police arrested several protesters at the demonstration.
Die Polizei verhaftete mehrere Demonstranten bei der Demonstration.
•
She joined the group of environmental protesters.
Sie schloss sich der Gruppe der Umweltprotestler an.