decomposition

Etymology

The current word, the separation of something into its parts, is probably borrowed from French décomposition,^[2][3][4] from décomposer (“to decompose”),^[2][3] formed from dé- and composer (“to compose”);^[5][2] the OED notes the French word in this sense in the Academy's dictionary of 1694, the probable source of the English use.^[5] The OED and Etymonline also treat it as a noun of action from decompose in English,^[5][6] which Etymonline forms from de- and composition,^[6] and Klein too forms it from the privative prefix and that noun.^[7] An earlier, obsolete sense, further compounding, belongs with decomposite and decompound, with the prefix in an intensive sense;^[5][6][4] Johnson derived that word from Latin dēcompositus.^[8] Merriam-Webster takes it as probably from that adjective, on the pattern of composite and its noun.^[2]

Earliest recorded meaning

Further compounding, the compounding of things that are already composite: 1659, in O. Walker's Some Instructions Concerning the Art of Oratory;^[5] this sense was obsolete by the end of the 17th century.^[5][4] Johnson (1755) still defined the word as "the act of compounding things already compounded".^[8]

Semantic evolution

The modern sense, the separation of something into its chemical elements, or of light into its colours, appears in 1762.^[5][6] The figurative use, of immaterial things, is recorded in the same year, in Walpole.^[5] From 1777, in Priestley, it also meant the natural breaking up of compound bodies: organic decay and putrefaction,^[5] the sense Etymonline dates for the verb decompose by 1777.^[6]

Timeline

• 1659 – further compounding of things already composite (obsolete by 1690).^[5]
• 1762 – separation of a substance into its elements, or of light into colours.^[5][6]
• 1762 – figurative, of immaterial things.^[5]
• 1777 – organic decay, putrefaction.^[5]

Meanings

Noun

1. The act or process of decomposing, or the state of being decomposed.^[2]
2. The separation of a substance into its parts or elements, or into simpler compounds: the decomposition of water into hydrogen and oxygen.^[2][5]
3. Organic decay; putrefaction: Cold slows the decomposition of the leaves.^[2][5]
4. Gradual breaking up; disintegration or dissolution, also figuratively.^[2][5]
5. (obsolete, 1659–1690) The compounding of things already composite.^[5][2][4]

Word family

• decompositional
• photodecomposition
• double decomposition

Related words

• decompose
• compose
• composition
• decomposite
• decompound

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
3. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
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 c d e f g h i j k l m n o p q Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
6. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
8. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.