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quantum

Etymology and origin of the English word quantum

History Permalink
Confidence
Established
Formation
Borrowing
First attested
1567
Borrowed from
Latin quantum
Ultimate origin
Latin (quantum)

Pronunciation

  • IPA: /ˈkwɒntəm/ (UK); /ˈkwɑntəm/ (US)[1]

Etymology

It is borrowed from Latin quantum (“how much, as much as”), the neuter singular of quantus, how great (see quantity).[2][3][4]

Earliest recorded meaning

A sum or amount: 1567 in Merriam-Webster, 1619 in Barnhart and the OED (in Purchas' Microcosmus), the 1610s in Etymonline.[4][2][5][3]

Semantic evolution

One's share or portion is from 1649.[5] Max Planck introduced the word into physics directly from Latin in 1900, for the minimum amount of a quantity that can exist, and Einstein reinforced it in 1905;[3][6] the physical sense is first recorded in English in 1910.[2][5] Quantum theory is from 1912 and quantum mechanics from 1922.[3] A quantum leap (mid-20th century), strictly a tiny change of state, is used popularly for a sudden large advance.[6]

Timeline

  • 1567 – an amount.[4]
  • 1649 – a share.[5]
  • 1910 – a unit of energy (physics).[2]
  • 1912 – quantum theory.[3]
  • 1922 – quantum mechanics.[3]

Modern meaning

Noun

  1. (physics) The smallest amount of a physical quantity, such as energy, that can exist independently.
  2. A quantity or amount, especially a specified one.
  3. A specified portion or share.

Adjective

  1. Sudden and significant, as in a quantum increase.

Word family

  • quantize

Usage notes

Word Origins notes the paradox that a quantum leap, used for a dramatic advance, in physics describes a very small change.[6]

References

  1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  3. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ a b c Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  5. ^ a b c d Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
  6. ^ a b c Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press

Related etymologies

Cite this entry

“Quantum.” Etymologically, 17 Oct. 2026, etymologically.com/en/quantum. Accessed 17 Oct. 2026.

Last edited on . ·