opportunistic

Etymology

It is formed from English opportunist + -ic.^[2][3][4][5] Opportunist is formed from opportune and -ist, probably after opportunism or German Opportunist, with Italian opportunista;^[2] Merriam-Webster takes it from French opportuniste.^[6] According to Etymonline the word belonged first to Italian politics, and in France opportuniste was used mockingly of the moderate Léon Gambetta in 1876.^[5] Opportune goes back to Latin opportūnus (“fit, convenient, timely”),^[2][5][7] from the phrase ob portum veniēns (“coming toward the harbour”), said of a wind,^[5][7] from ob (“toward”) and portus (“harbour”).^[5][7]

Earliest recorded meaning

Characterized by opportunism, taking advantage of circumstances without regard to principle, at first especially in politics: Merriam-Webster dates it to 1879,^[6] Etymonline to 1889^[5] and the OED to 1892, in the Speaker.^[2]

Semantic evolution

The political sense widened to any behaviour that seizes whatever chance arises.^[2][6] In the 1960s biology took the word up twice: in ecology, from 1960, for species that quickly occupy new or unexploited habitats,^[2][3] and in medicine, from 1961, for organisms that are normally harmless but cause disease when the host's resistance is weakened, and for the infections they cause.^[2][8][9]

Timeline

• 1879 – characteristic of an opportunist.^[6] Etymonline dates it to 1889, and the OED to 1892.^[5][2]
• 1960 – ecology, of species suited to newly formed habitats.^[2]
• 1961 – medicine, of organisms that cause disease only in a weakened host.^[2]

Meanings

Adjective

1. Taking advantage of opportunities as they arise, especially without regard to principles or consequences: an opportunistic politician.^[9][6][2]
2. (ecology) Of a species, quick to spread into new or unoccupied habitats.^[2][3]
3. (medicine) Of a microorganism, usually harmless but able to cause disease when the host's immune system is weakened; of an infection, caused by such an organism.^[9][6][8][2]

Word family

• opportunistically
• unopportunistic
• opportunistic infection

Related words

• opportunist
• opportunism
• opportunity
• opportune
• port

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 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
4. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
5. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
8. ^ a b Stedman's Medical Dictionary, Baltimore: Lippincott Williams & Wilkins
9. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins