penumbra

Definition

A partially shaded area around the edges of a shadow, especially an eclipse.

Etymology

From New Latin pēnumbra, from Latin paene (“almost”) + umbra (“shadow”).

Example Sentences

• "[A]ny penumbral fringe that may be detected cannot be well distinguished from the effects of the true penumbræ; […]"
• "The other places see the penumbra of the moon's shadow fall on the earth, so the eclipse is partial, and part of the sun's disc is still visible."
• "In the boiling temperature of 119 ° F – the hottest they had experienced so far – they watched as the penumbra of Venus blurred its outline at the precise moment the disc crossed the sun."