Definition of penumbra
penumbraeplay \-(ˌ)brē, -ˌbrī\ or
1a : a space of partial illumination (as in an eclipse) between the perfect shadow on all sides and the full lightb : a shaded region surrounding the dark central portion of a sunspot
2 : a surrounding or adjoining region in which something exists in a lesser degree : fringe the seventeenth century lay in the penumbra of the middle ages — Edward Eggleston
3 : a body of rights held to be guaranteed by implication in a civil constitution the penumbra of the Bill of Rights
4 : something that covers, surrounds, or obscures : shroud a penumbra of secrecy a penumbra of somber dignity has descended over his reputation — James Atlas
penumbralplay \-brəl\ adjective
Examples of penumbra in a sentence
the lunar eclipse began with a subtle darkening of the lunar surface as it passed within the Earth's penumbra
a penumbra of despair fell over the doomed city
Did You Know?
Every solar eclipse casts an umbra, the darker central area in which almost no light reaches the earth, and a penumbra, the area of partial shadow where part of the sun is still visible. Penumbra can thus be used to describe any "gray area" where things aren't all black and white. For example, the right to privacy falls under the penumbra of the U.S. Constitution; though it isn't specifically guaranteed there, the Supreme Court has held that it is implied, and thus that the government may not intrude into certain areas of a citizen's private life. Because its existence is still shadowy, however, the Court is still determining how much of an individual's life is protected by the right to privacy.
Origin and Etymology of penumbra
New Latin, from Latin paene almost + umbra shadow — more at umbrage
First Known Use: 1665
Legal Definition of penumbra
1 : an area within which distinction or resolution is difficult or uncertain the public-private penumbra
2 : an extension of protection, reach, application, or consideration; especially : a body of rights held to be guaranteed by implication from other rights explicitly enumerated in the U.S. Constitution the First Amendment has a penumbra where privacy is protected from governmental intrusion — Griswold v. Connecticut, 381 U.S. 479 (1965) — see also Griswold v. Connecticut
penumbral\-brəl\ play adjective
Seen and Heard
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