a semicircular or polygonal termination or recess in a building, usually vaulted and used especially at the end of a choir in a church.

What is in an apse?

An apse is a semicircular recess, often covered with a hemispherical vault. Commonly, the apse of a church, cathedral or basilica is the semicircular or polygonal termination to the choir or sanctuary, or sometimes at the end of an aisle. ... The apse is separated from the main part of the church by the transept.

What does apse mean in English?

apse in American English

1. a semicircular or polygonal projection of a building, esp. one at the east end of a church, with a domed or vaulted roof. 2.