ˈaps noun
( -s )
Etymology: Medieval Latin & Latin; Medieval Latin apsis, absis apse of a church, from Latin, vault, arch, orbit of a heavenly body — more at apsis
1. : a projecting part of a building (as a church) usually semicircular in plan and vaulted ; specifically : the bishop's seat or throne in ancient churches usually in the apse at the eastern end of the choir — see basilica illustration
2.
[New Latin, from Latin]
: apsis 2