1590s, "phantom, ghost," a figurative use from Latin umbra "shade, shadow" (see umbrage). Astronomical sense of "shadow cast by the earth or moon during an eclipse" is first recorded 1670s. Meaning "an uninvited guest accompanying an invited one" is from 1690s in English, from a secondary sense among the Romans. Related: Umbral.
雙語例句
1. This includes the continuous survey of umbra and penumbra of the sunspot.
這包括對太陽黑子本影和半影持續的觀測.
來自辭典例句
2. This is a lighter area between the umbra and the edge of a shadow.
這是本影和陰影邊緣之間較亮的區域.
來自辭典例句
3. Only moon umbra totally puts on earth, the shadow area can watch the eclipse.
唯有在月球的本影投影在地球表面時, 在該區域的人才能夠觀測到日食.
來自互聯網
4. Umbra - You need Samples values equal to or greater than 2 to see any influence of this button.