Partial shadow (8)
I believe the answer is:
penumbra
(Other definitions for penumbra that I've seen before include "Outer shadow round object" , "Outer region of shadow" , "Area of half shade" , "Imperfect shadow" , "Ring around sunspot" .)
I believe the answer is:
penumbra
(Other definitions for penumbra that I've seen before include "Outer shadow round object" , "Outer region of shadow" , "Area of half shade" , "Imperfect shadow" , "Ring around sunspot" .)