cortex

Etymology

It is borrowed from Latin cortex (“bark of a tree, rind, husk”).^[2][3][4][5] Klein glosses the Latin word literally as "that which is stripped off" and derives it, like corium (“hide, leather”), from a base meaning "to cut, separate";^[6] Etymonline and the American Heritage Dictionary trace it to Proto-Indo-European *sker- (“to cut”).^[3][5] Barnhart notes that the Latin form replaced the earlier English cortice, recorded probably before 1425 in a translation of Chauliac's “Grande Chirurgie”;^[4] the Middle English word, from the Latin accusative corticem, meant a rind or crust, or a layer of the eye.^[7] Klein compares the sense development of bark, the rind of a tree.^[6]

Earliest recorded meaning

An outer shell or husk, used figuratively: 1653 in Barnhart,^[4] 1660 in the OED, in H. More's Explanation of the Grand Mystery of Godliness.^[2] Etymonline dates the word to the 1650s.^[3]

Semantic evolution

From the late 17th century the word named the bark of certain trees used in medicine, especially Peruvian or cinchona bark, a sense the OED records from 1680 to 1803.^[2][8] At the same time it was applied to any outer layer of a plant or animal body or of an organ (before 1676).^[2] The anatomical sense, the outer grey matter of the brain, is recorded from 1741,^[2][3][9] and the botanical sense, the tissue lying outside the vascular bundles, from 1875.^[2] The figurative sense "outer shell" died out by the mid 18th century.^[8][2]

Timeline

• before 1425 – the earlier form cortice, a rind or crust.^[7][4]
• 1653 – an outer shell or husk.^[4][3]
• before 1676 – an outer layer of a plant or animal body or of an organ.^[2]
• 1680 – the bark of trees used in medicine, especially Peruvian bark (obsolete by 1803).^[2]
• 1741 – the outer grey matter of the brain.^[2][3]
• 1875 – in botany, the tissue between the vascular bundles and the epidermis.^[2]

Meanings

Noun

1. The outer layer of an organ or structure, such as the kidney or the adrenal gland.^[10][11][8]
2. The outer layer of grey matter of the cerebrum (the cerebral cortex), and a similar layer of the cerebellum.^[10][11][8]
3. In botany, the tissue in stems and roots between the epidermis and the vascular tissue; also the bark of a stem.^[10][8]
4. The bark of certain plants, or the peel of certain fruits, used in medicine, such as cinchona bark.^[11][8][2]

Word family

• cortical
• cortico-
• subcortex
• corticolous

Related words

• corium
• excoriate
• cuirass
• shear

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
6. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
8. ^ a b c d e f Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
9. ^ Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press
10. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins
11. ^ a b c Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster