Masonry built over a wall opening by uniformly projecting from each side until the units meet at midpoint. No arch action is effected-not a true arch.

(architecture) an arch constructed of masonry courses that are corbelled until they meet

a structure capable of spanning a space

Corbels that meet over a span.

A corbel arch (or corbeled / corbelled arch) is an arch-like construction method which uses the architectural technique of corbeling to span a space or void in a structure, such as an entranceway in a wall or as the span of a bridge. A corbel vault uses this technique to support the superstructure of a building's roof.