It seems from context that a marche blanche is a sort of organized, silent, memorial service.
There is no "answer" option below your last message so I'm answering here.
You could find "Pleureur, -euse" in old French litterature too, but it's more about persons hired to cry during funerals, or persons crying a lot (see: https://www.cnrtl.fr/definition/pleureuse). Now, in the way it is used, the meaning is pejorative, as I told you.
I don't think we have one word for "mourners". Usually one would say : personnes en deuil, personnes endeuillées ; parents et proches du défunt (relatives and friends of the deceased). Here it's even more than that because the people who march are not necessarily close to the deceased, they may just sympathize and protest against what they see as police violence.
Of course. "En deuil" and "endeuillées" make sense. I believe that the old English word "weepers" was also used for hired mourners. That practice is no longer common, which is probably why we don't say it anymore. (although there was a company in the UK called Rent-a-Mourner that managed to stay in business till 2019)
The article you linked was interesting, but I noticed that it did not use any such term. It referred to "marcheurs" and to "participants", which makes sense for what they are describing. (They were not so much mourning as protesting.) I guess I would now say "les marcheurs portaient à l'origine des costumes blancs, symbolisant l'innocence."
This has all been very helpful.
"Pleureuse" means "crybaby", it's quite pejorative.
They wore white on this specific occasion, so maybe "historically" is a bit strong. I don't think that people still wear white during a "marche blanche", but this expression has become generic.
My pleasure, je vous en prie :)
I am learning many interesting things today.
What do you say then to describe those in mourning? ("mourners" is the most common English word for this)
"Weepers" is an older English term but it has mostly gone out of use. I made the incorrect assumption that the French might use a word like that.
(to weep = pleurer)