verb (used without object), fluc·tu·at·ed, fluc·tu·at·ing.

to change continually; shift back and forth; vary irregularly: The price of gold fluctuated wildly last month.
to move back and forth in waves.

verb (used with object), fluc·tu·at·ed, fluc·tu·at·ing.

to cause to fluctuate.

Origin of fluctuate

1625–35; < Latin fluctuātus undulated, past participle of fluctuāre to flow, equivalent to fluctu(s) a flowing (derivative of fluere to flow) + -ātus -ate1
Related formsnon·fluc·tu·at·ing, adjectiveun·fluc·tu·at·ing, adjective

Synonyms for fluctuate

1. See waver1. 2. oscillate.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fluctuating

Contemporary Examples of fluctuating

Historical Examples of fluctuating

  • Once more he sat listening to that whining, fluctuating wave.

    The End of Time

    Wallace West

  • Were that so, not only all morality, but all science and all knowledge were fluctuating as sand.

  • With what fluctuating emotions I looked forward to meeting him again!

    Ernest Linwood

    Caroline Lee Hentz

  • I do not like that fluctuating color, or that quick, irregular breathing.

    Ernest Linwood

    Caroline Lee Hentz

  • Man's own fluctuating opinion is the measure and standard of all things.

    Christianity and Greek Philosophy

    Benjamin Franklin Cocker

British Dictionary definitions for fluctuating



to change or cause to change position constantly; be or make unstable; waver or vary
(intr) to rise and fall like a wave; undulate

Word Origin for fluctuate

C17: from Latin fluctuāre, from fluctus a wave, from fluere to flow
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for fluctuating



1630s, from Latin fluctuatus, past participle of fluctuare "to undulate" (see fluctuation). Related: Fluctuated; fluctuates; fluctuating.

Online Etymology Dictionary, © 2010 Douglas Harper