pen·um·bra /pəˈnʌmbrə/
半影
pe·num·bra /pəˈnəmbrə/ 名詞
Pe·num·bra n.
1. An incomplete or partial shadow.
2. Astron. The shadow cast, in an eclipse, where the light is partly, but not wholly, cut off by the intervening body; the space of partial illumination between the umbra, or perfect shadow, on all sides, and the full light.
Note: ☞ The faint shade surrounding the dark central portion of a solar spot is also called the penumbra, and sometimes umbra.
3. Paint. The part of a picture where the shade imperceptibly blends with the light.
◄ ►
penumbra
n : a fringe region of partial shadow around an umbra
[also: penumbrae (pl)]