fluctuate

verb

fluc·​tu·​ate ˈflək-chə-ˌwāt 

-chü-ˌāt

fluctuated; fluctuating

intransitive verb

1

: to shift back and forth uncertainly

Oil prices fluctuated.

Temperatures fluctuated.

2

: to rise and fall in or as if in waves

The boat fluctuated on the rough sea.

transitive verb

: to cause to fluctuate

Synonyms

• change
• mutate
• shift
• snap
• vary

Choose the Right Synonym for fluctuate

swing, sway, oscillate, vibrate, fluctuate, waver, undulate mean to move from one direction to its opposite.

swing implies a movement of something attached at one end or one side.

the door suddenly swung open

sway implies a slow swinging or teetering movement.

trees swaying in the breeze

oscillate stresses a usually regular alternation of direction.

an oscillating fan

vibrate suggests the rapid oscillation of an elastic body under stress or impact.

the vibrating strings of a piano

fluctuate suggests constant irregular changes of level, intensity, or value.

fluctuating interest rates

waver stresses irregular motion suggestive of reeling or tottering.

the exhausted runner wavered before collapsing

undulate suggests a gentle wavelike motion.

an undulating sea of grass

Examples of fluctuate in a Sentence

His popularity has fluctuated during his term in office.

In the desert, the temperature fluctuates dramatically.

Recent Examples on the Web

His income has fluctuated in that time, but 2023 was a good year for the Bidens, with an additional $40,462 in income, compared to 2022. —Chris Morris, Fortune, 16 Apr. 2024

While the company generated just over $4 million in revenue in 2023, Trump Media’s valuation has fluctuated wildly since going public in March, at one point reaching more than $7 billion. —William Turton, WIRED, 15 Apr. 2024

Shortage levels have fluctuated in the decade since, but have been steadily trending up since 2021 — now reaching a record-high of 323 drugs in the first three months of 2024. —Deidre McPhillips, CNN, 12 Apr. 2024

The numbers have fluctuated, peaking at more than 16,000 in March 2023, according to the report, which tracked abortions in the state from April 2022 to September 2023. —Mackenzie Mays, Los Angeles Times, 12 Apr. 2024

Since then, the mortgage rate has fluctuated somewhere between 6-7%. —Molly Peck, USA TODAY, 10 Apr. 2024

Further, extreme weather swings wrought by climate change, like floods and droughts, cause nitrate levels in groundwater to fluctuate. —Laura Schulte, Journal Sentinel, 3 Apr. 2024

Look for the coolest spot where temperatures won’t fluctuate dramatically throughout the year. —Dave McIntyre, Washington Post, 28 Mar. 2024

Pricing by manufacturer between early last year and early this year fluctuated wildly, Cox Automotive data show. —Ethan Baron, The Mercury News, 31 Mar. 2024

Word History

Etymology

Latin fluctuatus, past participle of fluctuare, from fluctus flow, wave, from fluere — more at fluid

First Known Use

1604, in the meaning defined at intransitive sense 2

Kids Definition

fluctuate

verb

fluc·​tu·​ate ˈflək-chə-ˌwāt 

fluctuated; fluctuating

1

: to move up and down or back and forth like a wave

2

: to be constantly changing especially up and down

fluctuation

ˌflək-chə-ˈwā-shən 

noun