fluctuate

Etymology

It is borrowed from Latin fluctuātus (“undulated”), the past participle of fluctuō (“to undulate, move in waves”),^[2][3][4][5] from flūctus (“a wave, flow, current”),^[2][6][3][7] from the past participle of fluō (“to flow”),^[2][6][7][8] from Proto-Indo-European *bhleu- (“to swell, well up, overflow”).^[6] Barnhart allows that the verb may have developed from an earlier English adjective spelled the same way, meaning wavering,^[9] which the OED records from about 1632 and marks as obsolete,^[3] and the Concise Barnhart also suggests a back-formation from fluctuation.^[10] That noun is older, recorded from about 1450.^[9][7][11]

Earliest recorded meaning

Of a person, to pass back and forth between opinions or courses of action, to waver: 1634, in Row's Historie of Kirk.^[3][5][9] Etymonline dates the verb to the 1630s.^[2]

Semantic evolution

Although the Latin verb was about waves, the first English records are figurative: a person wavering in 1634, then things that vary or are unsettled in 1655, in Fuller's Church-History of Britain.^[3] The literal sense of moving like waves is first listed in Blount's Glossographia (1656) and is now rare.^[3][12] Johnson (1755) gave five senses, running from water rolling to and fro to being in an uncertain state and being irresolute, and his quotation from Addison already speaks of an estate "fluctuating in funds".^[13] Transitive uses followed but stayed rare: to unsettle in 1788, in F. Burney's diary, and to set in wave-like motion in 1850, in Tennyson's In Memoriam.^[3][12] Today the main sense is to vary irregularly, especially in amount.^[6][14]

Timeline

• 1634 – of a person, to waver or vacillate.^[3][5][9]
• 1655 – of things and conditions, to vary irregularly, to be unsettled.^[3]
• 1656 – to move like a wave or waves.^[3]
• 1788 – transitive, to unsettle.^[3]
• 1850 – transitive, to throw into a wave-like motion.^[3]

Meanings

Verb

1. To change or vary irregularly, especially in amount or level: Fuel prices fluctuated all winter.^[6][14][3]
2. Of a person, to waver or vacillate between opinions or courses of action: He fluctuated between law and medicine for a year.^[5][3][12]
3. To move like a wave; to rise and fall, or to be tossed up and down: now rare.^[5][14][3]
4. (rare) To set in wave-like motion, or to unsettle.^[5][3][12]

Word family

• fluctuant
• fluctuation

Related words

• fluent
• fluid
• flux

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ a b c d e f g h i j k l m n o p Oxford English Dictionary Online (accessed March 2026), 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 Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c d e The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
7. ^ a b c Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
8. ^ Skeat, Walter W. (1911), A Concise Etymological Dictionary of the English Language, new ed., 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. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
12. ^ 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
13. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
14. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins