umbra
noun /ˈʌmbrə/
/ˈʌmbrə/
(plural umbras, umbrae
(specialist) /ˈʌmbriː/
/ˈʌmbriː/
)- the darkest part of a shadow
本影(影子中光源完全照射不到的部分) - the area on the earth or the moon that is the darkest during an eclipse
compare penumbra(日食或月食期间地球或月球的)本影
词源late 16th cent. (denoting a phantom or ghost): from Latin, literally ‘shade’.