1. An incomplete or partial shadow.

2. <astronomy> 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.

The faint shade surrounding the dark central portion of a solar spot is also called the penumbra, and sometimes umbra.

3. The part of a picture where the shade imperceptibly blends with the light.

Origin: NL, fr. L. Paene almost + umbra shade.

(01 Mar 1998)

pentylenetetrazol, pentylenetetrazole, penultimate year assessment < Prev | Next > penwoman, P enzyme, peon, peony

Bookmark with: icon icon icon icon iconword visualiser Go and visit our forums Community Forums