Which term describes a semicircular recess found at the east end of a church?

The term that describes a semicircular recess found at the east end of a church is "apse." This architectural feature is often vaulted and typically houses the altar, making it a significant part of ecclesiastical buildings. The design of the apse has both functional and symbolic importance, serving as a focal point for worship and enhancing the spiritual ambiance of the space.

In contrast, the nave refers to the central part of a church intended to accommodate the congregation, which is usually a long and wide space, separating the laity from the chancel area. The transept is the area that crosses the main body of the church, creating a T-shape and often housing additional chapels or altars. The chancel is the area around the altar at the eastern end, which may include the apse, but does not specifically denote the semicircular recess characteristic of the apse itself. Thus, the correct answer effectively captures the unique architectural element specific to the east end of a church.