baptistery

 
Pronunciation: /ˈbaptɪst(ə)ri/
(also baptistry /-tri/)

noun (plural baptisteries or baptistries)

  • the part of a church used for baptism.
  • historical a building next to a church, used for baptism.
  • (in a Baptist chapel) a sunken receptacle used for baptism by total immersion.

Origin:

Middle English: from Old French baptistere, via ecclesiastical Latin from ecclesiastical Greek baptistērion, from baptizein 'immerse, baptize'