pacifier (n.)

late 15c., pacifien, "appease, allay the anger of (someone)," from Old French pacifier, paciifier, "make peace," from Latin pacificare "to make peace; pacify," from pacificus "peaceful, peace-making," from pax (genitive pacis) "peace" (see peace). Of countries or regions, "to bring to a condition of calm, to restore peace to," late 15c., from the start with suggestions of forced submission and terrorization. Related: Pacified; pacifying.