umbra

Etymology

It is borrowed from Latin umbra (“shade, shadow”),^{[2][3][4][5][6]} the noun behind umbrage and umbrella.^[3][7][8] Its further origin is uncertain.^[7] Klein and Partridge, following Ernout and Meillet, compare a Sanskrit word for darkness and Avestan andō (“blind”), and liken the ending to that of Latin tenebrae (“darkness”).^[7][8] The Latin noun lives on in Romanian umbră, Italian ombra and French ombre,^[7][2] while Spanish sombra and Portuguese sombra come from a verb Vulgar Latin *subumbrō (“to cast shade upon”).^[7]

Earliest recorded meaning

The shade of a dead person, a phantom or ghost: 1601, in Ben Jonson's Fountaine of Selfe-love.^[2][9] Barnhart dates the word to 1599,^[4] and Etymonline to the 1590s.^[3]

Semantic evolution

Although the Latin noun meant "shade", the English word begins with a figurative use, "ghost".^[3] The plainer senses followed in the 17th century: a mere shadow of something in 1635, and shade or shadow in 1638.^[2] The sense "uninvited guest who comes along with an invited one" continues a secondary use among the Romans,^[3] and is recorded in English from 1696, in S. Sewall's diary.^[2] Astronomy took the word up in 1679 for the shadow of the earth or moon in an eclipse,^[2][4] and it later narrowed to the part of a shadow that is complete, as against the penumbra.^[2][10] In 1788 the Encyclopædia Britannica applied it to sunspots,^[2] where it means the dark centre,^[4] and in 1851 J. J. Sylvester gave it a sense in algebra.^[2]

Timeline

• 1601 – the shade of a dead person, a ghost.^[2][9]
• 1635 – a mere shadow of something, figuratively.^[2]
• 1638 – shade, shadow.^[2]
• 1679 – the shadow cast by the earth or moon in an eclipse.^[2][4] Etymonline has the 1670s.^[3]
• 1696 – an uninvited guest accompanying an invited one.^[2] Etymonline has the 1690s.^[3]
• 1788 – the dark centre of a sunspot.^[2][4]
• 1851 – in algebra, a symbol that must be paired with another to denote a quantity.^[2]

Meanings

Noun

1. (astronomy) The region of complete shadow cast by an opaque body, especially the moon's shadow on the earth during a solar eclipse: Observers on the ridge watched the umbra sweep across the plain.^[11][2][9]
2. (astronomy) The darker central part of a sunspot.^[11][2][4]
3. A ghost or phantom.^[9][2][10]
4. Someone who tags along with another; especially, an uninvited guest who comes with an invited one.^[9][2][6]
5. A shaded area; shade or darkness.^[9][2]
6. (algebra) A symbol that must be paired with another to denote a quantity.^[2]

Word family

• umbral

Related words

• penumbra
• adumbrate
• umbrella
• umbrage
• umbel
• umber
• somber
• sombrero

Usage notes

The plural is umbras or umbrae.^[9][11] The OED and the Shorter Oxford also list a rare noun umbra for a fish: the grayling, from 1610, and a sea fish of the genus Umbrina, from 1753; the OED takes its Latin source to be perhaps the same as this one.^[2][10]

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v w Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f g Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
5. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
6. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
7. ^ a b c d e Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
8. ^ a b Partridge, Eric (1966), Origins: A Short Etymological Dictionary of Modern English, 4th ed., London: Routledge & Kegan Paul
9. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
10. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
11. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins