fluctuate
gb/flˈʌkt͡ʃuˌeɪt/ us/flˈʌkt͡ʃuˌeɪt/
B2
English
Senses
0 senses
Verb
B2
process
1
vary up and down
If something fluctuates, it goes up and down.
Usage pattern:
[quantity] fluctuates (between [a] and [b]) (around [level])
Common mistake:
Often used intransitively: say “Prices fluctuate,” not usually “fluctuate prices.”
Synonyms
vary (More general; can be regular or irregular.)
|
swing (Suggests larger or more dramatic changes.)
|
change (Broader; does not specifically imply up-and-down movement.)
Antonyms
stabilize (Become steady after changing.)
|
remain steady (Continue without noticeable change.)
Collocations
prices fluctuate
|exchange rates fluctuate
|temperatures fluctuate
|levels fluctuate
|demand fluctuates
|sales fluctuate
|profits fluctuate
|fluctuate wildly
|fluctuate slightly
|fluctuate significantly
Themes
business
|money
|weather
|numbers
|data
Examples
- Gas prices fluctuate from week to week.
- Temperatures can fluctuate a lot in early spring.
- The value of the currency fluctuated sharply after the announcement.
Learner examples
- Prices fluctuate during the year.
- My weight fluctuates a little.
Verb
C1
process
2
change back and forth
If someone fluctuates, they keep changing from one state to another.
Usage pattern:
[someone/something] fluctuates between [state A] and [state B]
Common mistake:
Do not confuse with “hesitate” (pause before acting). “Fluctuate” emphasizes repeated changes over time.
Synonyms
waver (Often about confidence, voice, or commitment; can imply weakness or uncertainty.)
|
oscillate (More formal; often suggests repeated back-and-forth between two options.)
|
shift (Less explicit about repeated back-and-forth changes.)
Antonyms
be consistent (Stay the same in behavior or quality.)
|
settle (Become stable after a period of change.)
Collocations
mood fluctuates
|symptoms fluctuate
|confidence fluctuates
|energy levels fluctuate
|fluctuate between optimism and pessimism
|fluctuate between doubt and certainty
|fluctuate throughout the day
|fluctuate over time
Themes
emotions
|health
|relationships
|psychology
Examples
- Her mood fluctuated between excitement and anxiety.
- The patient’s symptoms can fluctuate, so daily check-ins are important.
- Public support fluctuates when the issue is in the news.
Learner examples
- My mood fluctuates when I am tired.
Verb
technical
C1
process
3
show random small variation
In science, if a value fluctuates, it changes a little in an irregular way.
Usage pattern:
[measurement/signal] fluctuates (around [mean])
Synonyms
vary (Neutral and common in technical writing.)
|
oscillate (Often implies a more regular pattern than random fluctuation.)
Antonyms
remain constant (Show no change over time.)
Collocations
signal fluctuates
|measurements fluctuate
|values fluctuate around the mean
|noise fluctuates
|fluctuate randomly
|fluctuate over time
|fluctuate within a range
Themes
science
|statistics
|technology
|data
Examples
- The sensor readings fluctuated slightly due to electrical noise.
- In a small sample, results may fluctuate around the true value.
- The laser intensity fluctuated as the temperature changed.
Grammar
Dictionary form
fluctuate
IPA
GB/flˈʌkt͡ʃuˌeɪt/
US/flˈʌkt͡ʃuˌeɪt/
Syllables & stress
fluc - tu - ate (3 syllables)
Stress on 1st syllable (fluc)
Word forms
Verb
- Base: fluctuate
- 3rd Person Singular: fluctuates
- Present Participle: fluctuating
- Past: fluctuated
Word family
Forms
fluctuates
verb
fluctuating
verb
fluctuated
verb
Core family
fluctuation
noun B2
Expressions
fluctuate around [a level]
1/flˈʌkt͡ʃuˌeɪt ɚˈaʊnd ə lˈɛvəl/
fixed phrase
stay near a typical level
It changes a little but stays near the same number.
Examples
- Unemployment has fluctuated around 5% for months.
- The share price fluctuated around $30 most of the year.
- The results fluctuated around the expected value.
fluctuate between [a] and [b]
1/flˈʌkt͡ʃuˌeɪt bɪtwˈin ə ˈænd bˈi/
fixed phrase
vary between two values
It goes up and down between two numbers or states.
Examples
- Attendance fluctuates between 80 and 120 people.
- Her pain levels fluctuated between mild and severe.
- The temperature fluctuated between 10°C and 18°C.
fluctuating fortunes
1/flˈʌkt͡ʃuˌeɪtɪŋ fˈɔɹt͡ʃunz/
fixed phrase
changing success and failure
Sometimes things go well and sometimes badly.
Examples
- The documentary follows the band’s fluctuating fortunes over two decades.
- Investors worried about the company’s fluctuating fortunes.
- After a few years of fluctuating fortunes, the team finally won the league.