penumbra

English · Español · Deutsch · Português · Română · Thesaurus

AI In plain words

Writing a short explanation…

Written by a house AI from the entry below, in your language. The entry itself is the source.

penumbra

  • /pəˈnʌm.bɹə/

Where it comes from

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

noun penumbras · penumbrae · penumbræ · pænumbra

  1. A partially shaded area around the edges of a shadow, especially an eclipse. [A]ny penumbral fringe that may be detected cannot be well distinguished from the effects of the true penumbræ; […]
  2. A region around the edge of a sunspot, darker than the sun's surface but lighter than the middle of the sunspot. The atmosphere was very clear, evidenced by the steadiness with which the mottling of the sun’s surface and the penumbræ of several spots were visible.
  3. figuratively An area of uncertainty or intermediacy between two mutually exclusive states or categories. These firms or businesses are not illegal in the strict sense, but there is a shadowy penumbra within which they live, and it is often convenient for the government to look the other way.

    Similar: grey area

  4. figuratively An area that lies on the edge of something; a fringe. Thank God we are not all cowards, we have not all a low ambition, which would make men shades, pœnumbræ^([sic]) of their fellows.

    Similar: periphery, outskirt

  5. Something related to, connected to, and implied by, the existence of something else that is necessary for the second thing to be full and complete in its essential aspects. The foregoing [United States Supreme Court] cases suggest that specific guarantees in the Bill of Rights have penumbras, formed by emanations from those guarantees that help give them life and substance.
  6. after a stroke A region of the brain that has lost only some of its blood supply, and retains structural integrity but has lost function.

Translations

Every language

noun partially shaded area around a shadow, especially an eclipse

Españolpenumbra
한국어본그림자 bon'geurimja, 본영 bonyeong
日本語半影 han'ei
中文半影 bànyǐng
Portuguêspenumbra
Françaispénombre
DeutschHalbschatten
Italianopenombra
Ελληνικάπαρασκιά paraskiá
Românăpenumbră
Русскийполуте́нь poluténʹ
العربيةشِبْه ظِلّ šibh ẓill
עבריתצל חלקי tsel khelkí

noun region around a sunspot

Españolpenumbra
Françaispénombre
DeutschPenumbra

Talk about this word

Cite this
MLA

"penumbra." Wiktionary, via Micwyn, micwyn.com/word/penumbra. Accessed 6 Nov. 2026.

APA

penumbra. (n.d.). In Wiktionary, via Micwyn. Retrieved November 6, 2026, from https://micwyn.com/word/penumbra

Chicago

"penumbra." Wiktionary, via Micwyn. Accessed November 6, 2026. https://micwyn.com/word/penumbra.

BibTeX
@misc{penumbra_2026,
  title = {penumbra},
  howpublished = {Wiktionary, via Micwyn},
  year = {2026},
  url = {https://micwyn.com/word/penumbra},
  urldate = {2026-11-06}
}