penumbra
E: Penumbra - "the partially shaded outer region of the shadow cast by an opaque object." (Merriam Webster)
penumbra
E: Penumbra - "the partially shaded outer region of the shadow cast by an opaque object." (Merriam Webster)
elliptical
E: Penumbra - "the partially shaded outer region of the shadow cast by an opaque object." (Merriam Webster)