fluctuation

Etymology

It is inherited from Middle English fluctuacioun,^[2][3] borrowed from Latin fluctuātiō (“a wavering motion, vacillation”), either directly or through French,^[4][5][6] where Old French fluctuacion is recorded from the 12th century.^[7] The Latin noun is formed from the past participle stem of fluctuō (“to undulate, move in waves”),^[4][7][6] from fluctus (“a wave, surge, flowing”), from the past participle of fluō (“to flow”),^[7] the source of fluent.^[7]

Earliest recorded meaning

Wavering between one opinion or feeling and another, vacillation: about 1450, in a translation of Thomas à Kempis's De Imitatione Christi,^[4] and in the same years in Capgrave's life of St Augustine, which explains fluctuacion as a man's doubt whether to take the good way or not.^[2]

Semantic evolution

The first English sense was mental, a wavering of mind, which the Middle English Dictionary glosses as vacillation or hesitation.^[2][4] The literal Latin image of waves came into English later: from 1620 the word was used in medicine of the movement of fluid in a cavity or tumour, and since 1646, in Sir Thomas Browne, of a wave-like rise and fall, a physical sense now rare.^[4] Johnson (1755) gave "the alternate motion of the water" first, quoting Browne, and "uncertainty; indetermination" second.^[8] From 1610 the word was used of passing from one state to another, and since 1802 of a rise and fall in amount, price, value or temperature, its main modern sense.^[4][3] In biology it has also meant a variation caused by the environment rather than by heredity.^[3][9]

Timeline

• c. 1450 – wavering of mind, vacillation.^[4][2]
• 1610 – passing rapidly from one state to another; repeated variation.^[4]
• 1620 – in medicine, the movement of fluid in a cavity or tumour.^[4]
• 1646 – a motion like that of waves, a rise and fall.^[4]
• 1802 – a rise and fall in amount, price, value or temperature.^[4]

Meanings

Noun

1. Repeated rise and fall or irregular change, as in prices, numbers or temperature: sharp fluctuations in the price of fuel.^[3][9][4]
2. A wavering or unsteadiness of opinion or feeling; vacillation.^[3][9][4][5]
3. A motion like that of waves; undulation.^[3][9][4]
4. (biology) A slight variation that is caused by the environment and is not heritable.^[3][9]
5. (medicine) The wave-like movement of fluid collected in a body cavity.^[3][4]

Related words

• fluctuate
• fluent

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
3. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
4. ^ a b c d e f g h i j k l m n o Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
5. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
9. ^ a b c d e Collins English Dictionary (2023), Glasgow: HarperCollins