penumbra

noun
1
an area of shadow which is between fully dark and fully light
نیم‌سایه, سایه‌ر‌وشن, سایه نیمه‌روشن
2
the shadow made by the earth or the moon during a partialeclipse
سایه‌ی نیمه‌تاریک, نیم‌سایه
compare umbra