isolate

Etymology

The verb is a back-formation from isolated,^{[2][3][4][5][6][7][8]} which is recorded from 1763 and is borrowed from French isolé (“isolated”) with the English suffix -ate added.^[3][9] The French word comes from Italian isolato (“detached”), the past participle of isolare (“to isolate”), from isola (“island”), from Latin insula (“island”).^{[9][10][11][3]} Barnhart gives the Italian source as insulātus (“made into an island”).^[3] The OED and the Shorter Oxford allow that the verb was partly modelled on isoler, recorded from 1690.^[2][8] The adjective and noun isolate (1819) come from Italian isolato or Medieval Latin insulātus according to the OED and Etymonline;^[2][4] Merriam-Webster derives them instead from the verb, after pairs such as appropriate.^[6] The word is thus a doublet of insulate.^[3][9]

Earliest recorded meaning

To place apart or alone, to detach: by 1786 in Etymonline;^[4] Merriam-Webster dates it to 1799,^[6] when The British Critic called it "unnecessary and foolish", among other French borrowings;^[4] the OED and Barnhart have 1807.^[2][3] Weekley quotes Todd's verdict on isolated, "a most affected word".^[11]

Semantic evolution

In the 19th century the verb was taken into the sciences: in chemistry, to obtain a substance in a pure form (1836); in electricity, to insulate (1855); and in medicine, to cut off an infected person or place from others, to quarantine (1888).^[2][8] The noun, something isolated, especially something taken out of its context for study, is recorded from 1890,^[2][4][6] and the 20th century added technical uses in perfumery (1923), microbiology, for a pure culture of micro-organisms (1931), social psychology, for a person cut off from normal social contact (1942), biology (1948) and linguistics (1949).^[2][8] The intransitive verb, to keep oneself apart from others, especially to isolate oneself at home, is recorded from 1988.^[2]

Timeline

• 1763 – isolated.^[3]
• 1786 – verb, to set apart, detach.^[4]
• 1799 – condemned as a French borrowing in The British Critic.^[4][6]
• 1807 – first OED quotation for the verb.^[2][3]
• 1819 – adjective, isolated.^[2][6]
• 1836 – in chemistry, to obtain a substance in pure form.^[2]
• 1888 – to quarantine an infected person or place.^[2]
• 1890 – noun, something isolated.^[2][4][6]
• 1931 – a pure culture of micro-organisms.^[2]
• 1988 – intransitive, to isolate oneself.^[2]

Meanings

Verb

1. To set apart from others; to cause to be alone or cut off: Floods isolated the farm for a week.^[12][6][2]
2. To keep an infected person or animal apart from others; to quarantine.^[12][2]
3. In chemistry, to obtain a compound in a pure, uncombined form.^[12][2]
4. To obtain a pure culture of bacteria or other micro-organisms.^[12][8]
5. In electronics, to prevent interaction between circuits or components; to insulate.^[12][2]
6. To keep oneself apart from others, especially at home.^[2]

Noun

1. Something isolated, especially something singled out for study.^[6][2]
2. A person or group cut off from normal social contact.^[8][2]
3. In biology, a pure culture of micro-organisms, or a population that has become distinct from its parent species.^[8][2]

Adjective

1. (rare) Isolated.^[6][2][8]

Word family

• isolator
• reisolate

Related words

• insulant
• insular
• insulate
• insulation
• insulator
• isolatable
• isolated
• isolation
• isolationism
• isle
• peninsula

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