What term describes masonry units that project from a wall or chimney to support a beam or change its direction?

The term that describes masonry units that project from a wall or chimney to support a beam or alter its direction is "corbel." Corbels are structural elements made of brick, stone, or other materials that are designed to support weight above them, and they can also help redirect loads or provide additional support for elements like beams or archways. By projecting out from the wall, corbels create a sturdy point where weight can be transferred safely, allowing for the design flexibility in constructing walls, roofs, and chimneys.

In the context of its use, a corbel can often be seen in traditional and contemporary architecture, adding both functionality and aesthetic value to structural designs.