containment

Etymology

It is formed from English contain + -ment,^[2][3][4] and the OED compares Old French contenement.^[2] contain is from Old French contenir, from Latin contineō (“to hold together, enclose”), from com- (“with, together”) and teneō (“to hold”).^[3]

Earliest recorded meaning

The action or fact of containing, holding or restraining; also, in a sense now obsolete, bearing or behaviour: 1619, in T. Milles's translation of P. Mexía.^[2] The OED's 1989 edition, Merriam-Webster and Etymonline date the word to 1655 or the 1650s,^[5][6][3] and Dictionary.com to 1645–55.^[4]

Semantic evolution

The word was little used until 1947, when it became the name of the Western policy of checking the expansion of the Soviet Union;^[3][2] Etymonline associates it with the American diplomat George F. Kennan, who in an article in Foreign Affairs that year called for "a long-term, patient but firm and vigilant containment of Russian expansive tendencies".^[3] The OED's first record of the sense is from the Partisan Review of that year,^[2] and Collins describes it as a principle of US foreign policy from 1947 to the mid-1970s.^[7] In physics and engineering it later came to mean the confinement of a plasma in a fusion reactor,^[7] and a structure or system that keeps radioactive material from escaping from a reactor.^[8]

Timeline

• 1619 – the action of containing; restraint.^[2]
• 1655 – first record in Merriam-Webster and in the OED of 1989.^[6][5]
• 1947 – the policy of containing a hostile power.^[2][3]

Meanings

Noun

1. The act or condition of containing, holding or keeping something within limits; restraint or control: the containment of the oil spill.^[6][7][8]
2. A policy of checking the expansion or influence of a hostile power or ideology, especially that of the United States towards Communist states from 1947.^[6][7][8][2]
3. A structure or system designed to prevent the accidental release of radioactive material from a nuclear reactor.^[8]
4. (physics) The confinement of the plasma in a thermonuclear reactor, keeping it from reaching the walls of the vessel.^[7]

Word family

• biocontainment

Related words

• contain
• content
• continent

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
5. ^ a b Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
6. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b c d e Collins English Dictionary (2023), Glasgow: HarperCollins
8. ^ a b c d The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin