hemoglobin

Etymology

It is shortened from English from earlier hematoglobulin (1845),^{[2][3][4][5][6][7]} which was formed from hemato-, in the sense of hematin, and globulin.^[4][8][9] The American Heritage Dictionary and Wiktionary trace it ultimately to hematinoglobulin, from hematin and globulin.^[10][1] Klein credits the shortening to the German chemist Ernst Felix Immanuel Hoppe-Seyler,^[9] and the OED compares German Hämoglobin;^[5] Merriam-Webster classes the word as International Scientific Vocabulary.^[4] Hemato- comes from Ancient Greek αἷμα (haîma, “blood”),^[3][6][1] and globulin, a simple protein, from globule, formerly a word for a blood corpuscle,^[6][5] which is from Latin globulus, with the suffix -in.^[2][3]

Earliest recorded meaning

The colouring matter of the red blood corpuscles, which carries oxygen: 1862 according to Barnhart and Etymonline.^[2][3][6] The OED's first quotation is from 1869, in the New Sydenham Society's Biennial Retrospect, and Merriam-Webster also dates it to 1869;^[5][4] Dictionary.com gives 1865–70.^[7]

Semantic evolution

The word replaced several earlier names for the same substance, which the OED lists as cruorin, hæmatoglobulin, hæmoglobulin and hæmatoglobin.^[5] The OED describes it as a protein that can be split into haem and globin and that turns bright scarlet when it takes up oxygen, as oxyhemoglobin;^[5] the American Heritage Dictionary puts the proportions at about 6 percent heme and 94 percent globin.^[11]

Timeline

• 1862 – the oxygen-carrying pigment of the red blood cells.^[2][3][6] The OED's first quotation is from 1869.^[5]

Meanings

Noun

1. The iron-containing protein pigment of the red blood cells of vertebrates, which carries oxygen from the lungs to the tissues.^{[4][12][11][5]}
2. The dark purplish, crystallizable form of this pigment.^[4]

Word family

• hemoglobic
• carboxyhemoglobin
• deoxyhemoglobin
• ferrihemoglobin
• hemoglobinopathy
• hemoglobinuria
• methemoglobin
• oxyhemoglobin

Related words

• hemato-
• hemo-
• hematin
• globulin
• globule
• globin
• heme

Usage notes

Merriam-Webster gives haemoglobin as a less common spelling,^[4] and the Shorter Oxford heads the word haemoglobin and marks hemoglobin as American.^[13] Wiktionary calls hæmoglobin a dated spelling.^[1]

References

1. ^ a b c d e Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
3. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c d e f g h Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
6. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
8. ^ Gove, Philip Babcock, ed. (1961), Webster's Third New International Dictionary of the English Language, Unabridged, Springfield, Mass.: G. & C. Merriam
9. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
10. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
11. ^ a b The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin
12. ^ Merriam-Webster's Collegiate Dictionary (2003), 11th ed., Springfield, Mass.: Merriam-Webster
13. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press