carbohydrate

Etymology

It is formed from English carbo- + hydrate,^[2][3][4][5] modelled on German Kohlenhydrat, used by the chemist C. Schmidt in 1844.^[2] The compounds were named "hydrates of carbon" because their composition looked like carbon combined with water, though their structure is far more complex.^[3][6][7] The first element is the combining form of carbon,^[3][8] which is ultimately from Latin carbō (“a coal, glowing coal; charcoal”);^[3] the second is ultimately from Ancient Greek ὕδωρ (húdōr, “water”),^[2][8][3] from a suffixed form of Proto-Indo-European *wed- (“water; wet”).^[3]

Earliest recorded meaning

A compound of carbon, hydrogen and oxygen in which the hydrogen and oxygen are in the same proportion as in water: 1851, in the Chemical Gazette.^[2][3] Merriam-Webster dates it to 1853,^[6] Dictionary.com to 1865–70,^[5] and Barnhart and the 1989 edition of the OED to 1869.^[8][9]

Semantic evolution

The name reflects an early classification of these compounds as hydrates of carbon,^[6][7][3] with the hydrogen and oxygen in the ratio 2:1.^[2][4] It was kept for the class of sugars, starches and celluloses after their structure was found to be more complex.^[3][6] They are an important source of food and energy for animals,^[10][4] and the informal clipping carb is used for them.^[10]

Timeline

• 1851 – a compound of carbon, hydrogen and oxygen with hydrogen and oxygen in the proportion of water.^[2][3] Barnhart dates the word to 1869.^[8]

Meanings

Noun

1. Any of a large group of organic compounds of carbon, hydrogen and oxygen, including the sugars, starches and cellulose, made by green plants and an important source of food and energy for animals: Rice and potatoes are rich in carbohydrate.^[6][10][4]

Word family

• noncarbohydrate
• carbo-load
• complex carbohydrate
• simple carbohydrate
• carbohydrate loading

Related words

• carbon
• hydrate
• hydrogen
• carb

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h i j Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
6. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b Gove, Philip Babcock, ed. (1961), Webster's Third New International Dictionary of the English Language, Unabridged, Springfield, Mass.: G. & C. Merriam
8. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
9. ^ Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
10. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins