x1=m1 is shade-darkened/has shadow x2=c1 cast upon it by obfuscating/blocking/(at least semi-)opaque object x3=c2 from energy/light/transmission source x4=c3; x2 is the shadow-eclipse caste upon x1 by x3, blocking radiation from x4
Possible uses include (but are not limited to) lunar-style eclipses in which the eclipsed object (as seen from another object) is not physically blocked from sight by yet another object but is shaded from sight by the shadow cast upon it by some object (possibly the one from which the eclipse is viewed). There is no real physical difference between this and a solar-style eclipse (both rely on linear alignment of bodies), but the chosen vantage point varies among them and thus causes different interpretations of the same phenomenon of alignment. In other words, it is an eclipse in which the eclipsed object is viewed to be darkened by a shadow (caste upon it by some object) with no significant blocking/impeding body physically betwixt the eclipsed object and the object from which viewing of the eclipse occurs.