1 the central part of a SHADOW where it is completely dark （阴影的）本影，全影

2 a completely dark area on the earth caused by the moon, or a completely dark area on the moon caused by the earth, during an ECLIPSE (= a time when the moon is between the earth and the sun, or when the earth is between the moon and the sun) （日食或月食时的）本影 ☞Compare penumbra. 与penumbra比较。 ☞picture at shadow 见shadow插图