wythe: A continuous vertical section of masonry that is 1 unit in thickness. It may be independent of or interlocked with the adjoining wythe(s). A single wythe of brick that is not structural in nature is referred to as a veneer. A multiple-wythe masonry wall may be composed of a single type of masonry unit layered to increase its thickness and structural strength, or different masonry units chosen by function, such as an economical concrete block serving a structural purpose, and a more expensive brick chosen for its appearance.