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

1.
manifestant, protestataire
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.
La police a arrêté plusieurs manifestants lors de la manifestation.
•
She joined the group of environmental protesters.
Elle a rejoint le groupe de manifestants écologistes.