apses

noun

1. 1.A semicircular projection from a building, especially the rounded east end of a church that contains the altar.
2. 2.The bishop's seat or throne in ancient churches.
3. 3.A reliquary, or case in which the relics of saints were kept.
4. 4.The nearest and furthest points to the centre of gravitational attraction for a body in orbit. More usually called an apsis.
5. 5.An aspen tree.