Rybat

(Scottish) a dressed stone at the side of a door or window. Rybats are described as inband or outband depending on which way the tail of the stone is used, along the face of the wall - outband, or through the wall - inband.
Found on http://www.encyclo.co.uk/local/20935

Rybat

A stone forming part of the side of a window or door opening.
Found on http://www.maintainyourchurch.org.uk/ToolkitModules/Toolkit1Glossary/tabid/
No exact match found