Ok, so what was the holocaust?
Forced relocation? Mass killing? Both, and other things, so “cleansing”
Of who? Jews? Gypsies? Gays? Blacks? All of those, so not “religious” or “racial”. Instead, “ethnic”
Sadly, ethnic cleansing has happened repeatedly since (and before) then. It is the most precise, description that is not too narrow.
If we can’t name the crime, then how do we describe it or bring the guilty to justice?