baptistry

Meanings

1. A designated space within a church, or a separate room or building associated with a church, where a baptismal font is located, and consequently, where the sacrament of Christian baptism (via aspersion or affusion) is performed.
2. An indoor pool used for baptism by immersion.

Etymology

From Middle English baptistery, baptisterie, from Ecclesiastical Latin baptistērium, from Ancient Greek βαπτιστήριον (baptistḗrion); equivalent to baptism + -ry.