Transept

Illustrated Architecture Dictionary

Transept

The part of a cruciform church, projecting at right angles to the main building

In the interior, the transept is between the nave and the chancel.

In Gothic churches, the projections should be called "arms" but are often called the "transepts"

Examples from Buffalo architecture:

Illustration above: St. Mary of Sorrows / King Urban Life Center

St. Louis Roman Catholic Church

St. Francis Xavier Roman Catholic Church

Unitarian Universalist Church

First Presbyterian Church

Our Lady of Victory RC Basilica