C
Champfer: A surface made by cutting across the square angle of a stone block or piece of wood at an angle of 45 degrees to the other two surfaces.
Corbel: Timber or stone projection from a wall to support a horizontal structure, e.g. a beam.
Counterscarp: The outer slope of a ditch or bank.
Crenellation: Battlement or indented parapet consisting of alternating raised parts and indentations. A licence to crenellate was the equivalent of a licence to fortify.
Curtain Wall: Defensive enclosure wall, often connecting one tower with another.