A structure constructed between two adjacent walls to aid in the transition from a polygonal to a circular structure; as when a dome is constructed on top of a square room
n. A structure, such as a section of vaulting or corbeling, set diagonally across the interior angle between two walls to provide a transition from a square to a polygonal or more nearly circular base on which to construct a dome. To squeeze, twist, or draw together: squinched her eyes shut
A small arch thrown across the corner of a square room to support a superimposed mass, as where an octagonal spire or drum rests upon a square tower; called also sconce, and sconcheon