erupt

Etymology

It is borrowed from Latin ēruptus (“having burst forth”),^[2][3][4][5] the past participle of ērumpō (“to break out, burst forth”).^[6][7][8] Barnhart considers it a back-formation from eruption, at least in part,^[9][10] which English had acquired earlier, in the early 15th century,^[2][11] and the OED sees that noun's influence in the transitive senses.^[6] The Latin verb is formed from ē-, a variant of ex- (“out”), and rumpō (“to break”),^[9][2][7] from Proto-Indo-European *reup-.^[7] The same Latin verb is the source of rupture, rout, route and routine, and it is related to bereave, rob and robe.^[11]

Earliest recorded meaning

To burst forth in the course of growth: 1657, in R. Tomlinson's translation of J. de Renou's work on medicines.^[6] Barnhart and Merriam-Webster Unabridged also give 1657,^[9][4] and Etymonline has the 1650s, of diseases and the like.^[2]

Semantic evolution

The first uses were medical and bodily: the OED's oldest sense now applies only to teeth breaking through the gums,^[6] and a rash or boil can also be said to erupt.^[5][12] The volcanic sense, now the most familiar, came more than a century later: Etymonline dates it to 1770, noting that the Latin word had been used of Mount Etna,^[2] and the OED first finds it in William Hamilton's reports to the Royal Society, transitively in 1771 (a volcano throwing out matter) and intransitively in 1772.^[6] A river was said to burst forth in this way in 1864.^[6] The verb is also used of people and of sudden noise or violence, as when an audience breaks into laughter or a kingdom into rebellion.^[12][4]

Timeline

• 1657 – to burst forth in growth.^[6][9]
• 1771 – of a volcano or geyser, to throw out matter.^[6] Etymonline has 1770 for the volcanic use.^[2]
• 1772 – of a volcano or geyser, to be in eruption.^[6]
• 1859 – transitive, to force teeth through the gums.^[6]
• 1864 – of a river, to burst forth.^[6]

Meanings

Verb

1. Of a volcano or geyser, to throw out lava, steam or ash with force; of such matter, to be thrown out: The crater erupted twice in one winter.^[5][4][6]
2. To burst out suddenly and violently, as if released from a restraint: Water erupted from the broken main.^[5][4]
3. To break suddenly into noise, anger or violence: The stadium erupted in cheers when the ball went in.^[4][12][5]
4. Of a rash or boil, to appear on the skin.^[5][12]
5. Of a tooth, to come through the gum.^[5][6][12]

Word family

• eruptive
• eruptively
• eruptible
• unerupted

Related words

• eruption
• rupture
• rout
• route
• routine
• bereave
• rob
• robe
• irrupt

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
4. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c d e f g Collins English Dictionary (2023), Glasgow: HarperCollins
6. ^ a b c d e f g h i j k l m Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
7. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
8. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
9. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
10. ^ Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
11. ^ a b Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
12. ^ a b c d e Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press