penumbra

noun

pə-ˈnəm-brə How to pronounce penumbra (audio)
Definition of penumbranext
1
as in shadow
partial darkness due to the obstruction of light rays the lunar eclipse began with a subtle darkening of the lunar surface as it passed within the Earth's penumbra

Synonyms & Similar Words

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Antonyms & Near Antonyms
2
as in veil
something that covers or conceals like a piece of cloth a penumbra of despair fell over the doomed city

Synonyms & Similar Words

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of penumbra During many eclipse seasons, the moon merely skims Earth's penumbra and umbra. — Jamie Carter, Space.com, 27 Feb. 2026 The partial outer shadow is called the penumbra; the full, dark shadow is the umbra. — Ashley Strickland, CNN Money, 31 Jan. 2026 For now, we’re held in the sweet penumbra of heaviness. — James Parker, The Atlantic, 16 Dec. 2025 The umbra is a darker inner shadow and the penumbra is a fainter outer shadow, according to NASA. — Melina Khan, USA Today, 6 Sep. 2025 See All Example Sentences for penumbra
Recent Examples of Synonyms for penumbra
  1. shadow
  2. veil
  3. shade
  4. shroud
  5. blackness
  6. cloak
  7. dusk
  8. pall
Noun
  • With 67% of employees engaging in shadow AI usage at work, this unapproved use of chatbots and other AI agents is potentially exposing companies’ sensitive data.
    — Ryan Grant, Forbes.com, 20 July 2026
  • This dominance is physically and mentally exhausting for opponents, who are left chasing shadows as Spain’s technicians pass around them with precision.
    — Dermot Corrigan, New York Times, 20 July 2026
Definition of shadow
Noun
  • Healy wore a classic black tuxedo, while Bechtel was dressed in a glamorous white gown with a traditional veil.
    — Ashlyn Robinette, PEOPLE, 19 July 2026
  • Today, Mars is wrapped in an atmosphere little more than a thin veil that is 100 times thinner than Earth's and slowly leaking into space.
    — Sharmila Kuthunur, Space.com, 17 July 2026
Definition of veil
Noun
  • Homes with too little tree coverage or that get a lot of direct afternoon sun will absorb more radiant heat that a home with natural shade.
    — Timothy Dale, The Spruce, 17 July 2026
  • As the sun moves across the sky, the dual awnings help maintain shade from different angles.
    — New Atlas, New Atlas, 17 July 2026
Definition of shade
Noun
  • In January, Banco Santander, Spain’s largest financial institution, moved to pull back the shroud of mystery that had enveloped the marquee collection.
    — Los Angeles Times, Los Angeles Times, 14 July 2026
  • Upon its ’01 debut at retail, the Air Jordan 16 introduced a first-of-its-kind feature to the Air Jordan line in the form of a removable shroud covering the shoelaces.
    — Riley Jones, Footwear News, 11 July 2026
Definition of shroud
Noun
  • Experts say that the biggest challenge at that extreme level of blackness is actually measuring it.
    — New Atlas, New Atlas, 26 June 2026
  • In the restaurant, my dad looked at me with the passionate conviction of a man who was confident in his Blackness and wanted nothing more than to pass it on.
    — Literary Hub, Literary Hub, 17 June 2026
Definition of blackness
Noun
  • Standard, off-the-shelf materials were insufficient, demanding an entirely new structure for the cloak.
    — Mrigakshi Dixit, Interesting Engineering, 14 July 2026
  • In our post-religious era—in which, beneath the cloak of secular humanitarianism, righteous religiosity and virtuous crusading remain as potent as ever—history has attained the authority, authenticity and prestige that religion and its prelates once possessed.
    — Simon Sebag Montefiore, The Atlantic, 28 June 2026
Definition of cloak
Noun
  • What’s Next In The Night Sky Over the next four weeks, the moon continues to wax, culminating in the rise — during dusk — of the full Buck Moon on July 29.
    — Jamie Carter, Forbes.com, 20 July 2026
  • This ring, traversing the sky for hours after dusk and before dawn, would outshine every star and planet, and be visible from every spot on Earth.
    — Tereza Pultarova, Space.com, 20 July 2026
Definition of dusk
Noun
  • The Dodgers had opened Pandora’s box, and out would fly a lockout, a pall of smoke over their games, and a plague of locusts.
    — Bill Shaikin, Los Angeles Times, 20 July 2026
  • But now, the idyllic Mississippi island is overcast with an unsettling pall after the death of 18-year-old Nolan Wells.
    — Marlene Lenthang, NBC news, 18 July 2026
Definition of pall

Browse Nearby Words

penultimate
penumbra
penumbrae
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Cite this Entry

“Penumbra.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/penumbra. Accessed 23 Jul. 2026.

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More from Merriam-Webster on penumbra

Britannica.com: Encyclopedia article about penumbra

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