Borrowed fromEcclesiastical Latinbaptistērium,baptizātōrium, fromAncient Greekβαπτιστήριον(baptistḗrion); equivalent tobaptiste +-erie.
baptisterie(chiefly Late Middle English, rare)
baptisterieoblique singular, f (oblique pluralbaptisteries,nominative singularbaptisterie,nominative pluralbaptisteries)