noun, plural bap·tis·ter·ies. 1.a building or a part of a church in
which baptism is administered.
2.(especially in Baptist churches) a tank for administering baptism by immersion.
Origin: 1425–75; <
Late Latin baptistērium <
Greek baptistḗrion bathing place (see
Baptist,
-ery); replacing
late Middle English baptizatory <
Medieval Latin baptizātōrium