endogenous

Etymology

The OED takes it as formed from English endogen + -ous,^[2] and Barnhart and Merriam-Webster Unabridged as French endogène with the English suffix;^[3][4] Etymonline and Dictionary.com analyse it as endo- and -genous.^[5][6][7] The French word was coined by de Candolle in 1813,^[2] from Ancient Greek ἔνδον (éndon, “within”) and -γενής (-genḗs, “born, produced”);^[2][3] a Greek ἐνδογενής (endogenḗs) is found with the sense "born in the house".^[2][3] It is the counterpart of exogenous.^[3][8]

Earliest recorded meaning

Of or belonging to an endogen, a plant thought to add new wood inside its stem: 1830, in John Lindley's Introduction to the Natural System of Botany.^[2][4][3] Etymonline dates the botanical use, "growing from within", to 1822.^[5]

Semantic evolution

The word began in botany, for a class of plants that included the cereals and palms,^[5][2] a use now rare or obsolete.^[7] It was extended in the 19th century to geology, for rocks formed within a rock mass or the earth's crust (1845),^[2][7] to anything growing from within (1856, in Emerson),^[2] and to pathology (1876).^[2] In psychiatry it has been used since 1925 for disorders, such as endogenous depression, that arise within the person and not from an outside cause.^[2][9] Modern dictionaries extend it to anything caused or produced inside an organism or system.^[4][9]

Timeline

• 1830 – of the endogens, in botany.^[2][4][3] Etymonline dates the word to 1822.^[5]
• 1845 – in geology, formed within a rock mass or the earth's crust.^[2]
• 1856 – growing or originating from within.^[2]
• 1876 – in pathology.^[2]
• 1925 – in psychiatry, of disorders that arise within the individual.^[2]

Meanings

Adjective

1. (biology) Produced or originating inside an organism or one of its parts: an endogenous hormone.^[9][4]
2. Caused by factors inside an organism or system, with no apparent outside cause: endogenous depression.^[9][4][2]
3. (botany) Growing from deep tissue rather than from the surface, as some roots do; formerly, of plants that add new tissue inside the stem.^[4][7][2]
4. (geology) Formed within a rock mass or beneath the earth's surface.^[7][2]

Word family

• endogenously
• endogeny

Related words

• exogenous
• endogen
• indigenous

Usage notes

Dictionary.com lists endogenous and indigenous as words that are easily confused.^[6]

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 m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f 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 Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ a b c d e Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
8. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins