antumbra

English

Diagram of a large light source and a smaller occulting body, showing the relationships between the umbra, the region that receives no light from the source, so that it is fully shaded, the penumbra that receives light from only one part of the rim of the source, so that it is partly shaded, and the antumbra, that is so far from the occulting body that it receives light from the rim all the way around the source, though not from the full area of the light source.

Etymology

From ante- (“before”) +‎ umbra (“shadow”).

Pronunciation

• IPA^(key): /ænˈtʌm.bɹə/, /ˈæn.tʌm.bɹə/

Noun

antumbra (plural antumbrae)

1. (rare) The region from which an occulting body appears entirely contained within the disc of the light source.

Related terms

English terms prefixed with ante-

• See umbra#Derived_terms

Anagrams

• rambutan