半はん陰いん影えい

noun

penumbra

Astronomical term for the partial shadow during an eclipse, where the light source is only partially blocked.

• 月げっ食しょくのとき、月つきが半はん陰いん影えいに入はいると少すこし暗くらく見みえる。

  During a lunar eclipse, when the moon enters the penumbra, it looks slightly darker.