umbra

 
Pronunciation: /ˈʌmbrə/

noun (plural umbras or umbrae /-briː/)

  • 1the 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. Compare with penumbra.
  • Astronomy the dark central part of a sunspot.
  • 2 [mass noun] literary shadow or darkness: an impenetrable umbra seemed to fill every inch of the museum

Derivatives

umbral

adjective

Origin:

late 16th century (denoting a phantom or ghost): from Latin, literally 'shade'