brightness

Etymology

It is inherited from Middle English brightnesse, also brihtnesse,^[2][3][4] inherited from Old English beorhtnes, also byrhtnes and bryhtnes,^[2][3][5][6] formed from beorht (“bright”) and -nes.^[2][5] The OED compares Old High German berahtnessī, either a cognate or a parallel formation from the same Germanic bases.^[7] The adjective goes back to Proto-Germanic *berhtaz (“bright”), from Proto-Indo-European *bhereg- (“to shine; bright, white”).^[3]

Earliest recorded meaning

The quality of giving out or reflecting light, already in Old English, in Wærferð's translation of Gregory's Dialogues.^[7] Bosworth–Toller glosses the Old English word as brightness, clearness and splendour, and quotes Godes beorhtnes him ymbesceán from Luke 2:9, for the Latin claritas Dei circumfulsit illos.^[5] Dictionary.com dates the word to before 950.^[6]

Semantic evolution

Physical light and glory stood side by side from the start: Old English used the word for shining, for a particular patch of light, and for splendour or renown.^[7][5] Later senses transfer it to the colour of things, from before 1475, and to clear, sunny weather, from 1656.^[7] Mental and temperamental senses follow in the 17th century: quickness of wit from 1655, in T. Fuller, and cheerful liveliness from 1660.^[7] Johnson (1755) gives only "lustre; splendour; glitter" and "acuteness".^[8] The scientific sense of measured intensity begins with R. Hooke in 1674;^[7] Collins calls brightness a former name in physics for luminosity, and adds the psychological sense of light intensity as it is experienced.^[9]

Timeline

• Old English – the giving out or reflecting of light; a particular patch of light; splendour, glory.^[7][5]
• 1340 – illumination, being full of light, in the Ayenbite.^[7]
• before 1475 – vividness of colour.^[7]
• before 1500 – happiness or prosperity, especially as a prospect, in a copy of Rolle's Psalter of about 1340.^[7]
• 1655 – intelligence, quickness of wit.^[7]
• 1656 – of the sky or weather, clear and sunny.^[7]
• 1660 – cheerfulness, liveliness.^[7]
• 1674 – in astronomy and physics, the intensity of light seen from a source.^[7]
• 1819 – of sound, a clear, vibrant and typically high-pitched quality.^[7]

Meanings

Noun

1. The quality of giving out or reflecting light; radiance: The brightness of the snow made her squint.^[9][2][7]
2. Vividness of colour.^[7][9]
3. Quick intelligence; sharpness of wit.^[2][7]
4. Cheerfulness or vivacity.^[7]
5. Splendour or fame.^[2][7]
6. Of sound, a clear, vibrant, usually high-pitched quality.^[7]
7. (physics) The intensity of light seen from a source; luminance.^[2][7]
8. (psychology) Light intensity as it is experienced by the viewer.^[9][2]

Related words

• bright
• brighten
• -ness

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
3. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ Stratmann, Francis Henry (1891), A Middle-English Dictionary, revised by Henry Bradley, Oxford: Clarendon Press
5. ^ a b c d e Bosworth, Joseph; Toller, T. Northcote (1898), An Anglo-Saxon Dictionary, Oxford: Clarendon Press; Toller, T. Northcote (1921), Supplement
6. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ a b c d e f g h i j k l m n o p q r s t u v Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
8. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
9. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins