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momentous

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Etymology and origin of the English word momentous

Confidence
Established
Formation
Derivation
First attested
1652 L. S., Natures Dowrie
Ultimate origin
Latin moveō
Etymology tree
inherited borrowed derived
English moment
English momentous

Pronunciation

  • UK: /məʊˈmɛn.təs/[1]
  • US: /moʊˈmɛn.təs/[1]

Etymology

It is formed from English moment + -ous,[2][3][4][5][6] with the noun in its sense of importance or weight;[2][3] Etymonline explains that the suffixed form carried the sense "important", while momentary kept that of an instant of time.[3] The noun comes from French moment and Latin mōmentum (“movement, impulse, influence, importance; a very short time”), from moveō (“to move”) and the suffix -mentum.[2][3]

Earliest recorded meaning

Having motive force: 1652, in L. S.'s Natures Dowrie, a sense that the OED and the Shorter Oxford record only in the mid 17th century.[2][5] Etymonline dates the word to the 1650s, in the sense "of moment or consequence".[3]

Semantic evolution

The sense of importance appears in 1656, in H. Jeanes's Mixture of Scholasticall Divinity, applied to things and events of great weight or consequence;[2][4] Dictionary.com dates the word to 1645–55.[6] From 1667 it was also used of a person or group having influence, a use the OED now calls rare;[2] Merriam-Webster quotes Melville's momentous men for the three mates of the Pequod.[4] Johnson (1755) defined it as important, weighty, of consequence.[7] A technical sense relating to momentum was recorded once, in the Philosophical Transactions of 1775.[2]

Timeline

  • 1652 – having motive force (obsolete).[2][5]
  • 1656 – of a thing or event, of great weight or consequence.[2][4]
  • 1667 – of a person, having influence or importance.[2]
  • 1775 – in physics, relating to momentum (rare, obsolete).[2]

Meanings

Adjective

  1. Of great importance or consequence; significant, weighty: a momentous discovery.[8][9][4][2]
  2. Of a person, having importance or influence.[4][2]
  3. (obsolete, 1652) Having motive force.[2][5]

Word family

  • momentously
  • momentousness
  • unmomentous

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 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  3. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  5. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  6. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  7. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
  8. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  9. ^ Collins English Dictionary (2023), Glasgow: HarperCollins
Cite this entry

“Momentous.” Etymologically, 2 Nov. 2026, etymologically.com/en/momentous. Accessed 2 Nov. 2026.

Last edited on . ·