The equivalent word is "synagogue service."
The Halocaust
The first part of the Mass, the Liturgy of the Word, or what used to be called the Mass of the Catechumens started out based on the syngogue service of the Jews during the time of Jesus.
The Germans at the time called it "the Final solution". The Jews to whom it was done call it the "holocaust". What ever it was called it was a genocide of massive proportions.
Operation Magic Carpet.
Adolf Hitler called it "The Final Solution" but the Allied Forces called it murder. They called it "The Holocaust".
The plan to kill all Jews was called the Final Solution, in which means that the mass murdering of Jews, in 1942 after the Final solution was decided, 3 million jews were murdered in a single year, 8,000+ dying daily.
Holocaust
Do you mean mass as in service? Or mass as in people?
People who practice Judaism are called Jews.
The term is genocide: deliberate & systematic mass killing of people
The Nazis killed mainly Jews in the holocaust but also people who were 'feeble minded', 'crippled', and even POWs.
They are called "Jews".