Is the Radical Line defined Inside two Intersecting Circles?

Question

It is given that, the radical line of two intersecting circles is the common chord of the two circles. In strict terminology, does the radical line refer to the region only outside the circles and the common chord only inside the two circles? Is there any strict terminology for radical line definition for outside or inside points, like a circle usually refers only the boundary, whereas a disc represents the region? Or the term radical line is used interchangeably with common chord in case of intersecting circles?