penumbral

American  

[pi-nuhm-bruhl] / pɪˈnʌm brəl /

Sometimes penumbrous

adjective

1. Astronomy.

   1. of, causing, or being the partial shadow outside the complete shadow of an opaque body, such as a planet, where the light from the source of illumination is only partly cut off.

      Four consecutive total lunar eclipses in a row, without any penumbral eclipses in between, are known as a tetrad.

   2. relating to or being the grayish marginal portion of a sunspot.

      An average eye can see a sunspot with a penumbral diameter of at least 41 arcseconds.

2. relating to or being a shadowy, indefinite, or marginal area.

   The apple trees provide penumbral lighting that is perfect for studying, thinking, or even a nap.

   While the beneficiaries of corruption fête themselves with cocktail nights and caviar dreams, its victims wander a penumbral existence.

3. U.S. Law. of or relating to the set of rights implicit in the U.S. Constitution or Bill of Rights.

   The wealthy, like everyone else, are entitled to the full enjoyment of the Constitution's express and penumbral guarantees.

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Etymology

Origin of penumbral

penumbra ( def. ) + -al ¹ ( def. )

Example Sentences

As the moon prepares to blot out the surface of our sun in two weeks, it’s warming up with a penumbral lunar eclipse on Sunday night or Monday morning, depending on your time zone.

From New York Times

In what’s known as a penumbral lunar eclipse, the full moon passed within the outer part of Earth’s shadow, causing the moon to dim only slightly.

From Seattle Times

Compositionally, this shot of a narrow, penumbral domestic space is a stunner.

From New York Times

The total lunar eclipse will begin as an unremarkable “penumbral” lunar eclipse — a subtle darkening hardly perceptible to the untrained observer.

From Washington Post

Or we can stay exactly where we are, in this state of gorgeous make-believe, this penumbral present, with its rich colors, heavy drapes and musty air of perfume, popcorn and potential.

From Washington Post