Optics either of two points on the optic axis of a lens or lens system such that the straight line joining one of them to a point on the object is parallel to the line joining the other to the corresponding point on the image.
Origin
Early 19th century.
Definition of nodal point in US English:
nodal point
noun
Optics either of two points on the optic axis of a lens or lens system such that the straight line joining one of them to a point on the object is parallel to the line joining the other to the corresponding point on the image.