Original: The term "Mass" is derived from the late-Latin word missa (dismissal), a word used in the concluding formula of Mass in Latin: "Ite, missa est" ("Go; it is the dismissal").
Simplified: The term comes from the late-Latin word missa (dismissal), a word used in the concluding formula of Mass in Latin: "Ite, missa est" ("Go, it is the dismissal").