decompose

Etymology

Most dictionaries take it as borrowed from French décomposer,^{[2][3][4][5][6][7][8]} a verb recorded in the 16th century,^[2][9] formed from dé-, expressing reversal, and composer (“to compose”).^[2][3][7] Barnhart and Etymonline instead treat it as formed in English from de- and compose, Barnhart allowing an influence of the French verb.^[10][11] The French verb goes back to Old French composer, from com- and poser (“to place”), from Late Latin pausō (“to cease, lay down”);^[11][2] its meaning was influenced by Latin compōnō (“to put together, arrange”).^[11][5]

Earliest recorded meaning

To separate something into its constituent parts or elements: before 1751, in the works of Viscount Bolingbroke.^[2][10] Merriam-Webster Unabridged dates this sense to 1718,^[3] and the Oxford Dictionary of English places the word in the mid 18th century.^[7]

Semantic evolution

The first sense was the separation of a thing into its components, used of chemical elements, of light split into colours and of other analyses.^[2][3] The sense "to rot, putrefy" followed by 1777 according to Etymonline;^[11] the OED's first example of the intransitive "to decay, break up" is from 1793, in Thomas Beddoes, and of the transitive "to cause to rot" from 1841.^[2] Weekley also dates the sense of putrefaction to the 18th century.^[12] Burke used it of immaterial things in 1796,^[2] and printers briefly used it for distributing set type (1816).^[2] The noun decomposition had first meant a further compounding of things already composite (1659), and took the sense of decomposing only in 1762.^[10]

Timeline

• before 1751 – to separate into constituent parts or elements.^[2][10]
• 1777 – to putrefy, become resolved into its elements.^[11] The OED's first example of the intransitive verb, to decay or break up, is from 1793.^[2]
• 1796 – figuratively, of immaterial things.^[2]
• 1816 – in printing, to distribute set type (obsolete).^[2]
• 1841 – transitive, to cause to disintegrate or rot.^[2]

Meanings

Verb

1. Of organic matter: to break down, or be broken down, through the action of bacteria or fungi; to rot: The fallen leaves decomposed over the winter.^[13][3][2]
2. (chemistry) To break down, or cause to break down, into simpler compounds or elements.^[13][3][2]
3. To separate into constituent parts.^[13][3][2]
4. To distinguish the parts of something by analysis.^[3]
5. (mathematics) To express something in terms of simpler independent components, as a vector as a sum of orthogonal components.^[13]

Word family

• decomposability
• decomposable
• decomposition
• undecomposed
• decomposer

Related words

• compose
• compost

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 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
4. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
6. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
8. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
9. ^ Skeat, Walter W. (1911), A Concise Etymological Dictionary of the English Language, new ed., Oxford: Clarendon Press
10. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
11. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
12. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
13. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins