umbra
noun
[ ˈʌmbrə ]
• the fully shaded inner region of a shadow cast by an opaque object, especially the area on the earth or moon experiencing the total phase of an eclipse.
• shadow or darkness.
• "an impenetrable umbra seemed to fill every inch of the museum"
Origin:
late 16th century (denoting a phantom or ghost): from Latin, literally ‘shade’.
