This is the 4548th most frequent French word.
manifestant
Protester.
Here, 'manifestant' is used as a noun referring to an individual participating in a demonstration.
Le manifestant a crié des slogans.
The protester shouted slogans.
In this case, 'manifestante' is the feminine form of the noun to match the gender of the individual being talked about.
Elle était manifestante pour la cause environnementale.
She was a protester for the environmental cause.
Here, the word 'manifestations' refers to the plural noun form indicating organized public protests, demonstrating a change in meaning to focus on the events themselves.