Translation guide
The English word "fluctuation" refers to irregular changes in level, amount, value, or state. In Japanese, the most common equivalent is 変動 (hendō), but depending on context, words like 変動, 上下, 増減, 変わり, 波, ゆらぎ, and others are used. This guide organizes Japanese expressions by the type of fluctuation.
To describe irregular changes in economic indicators, numerical values, or measurable levels.
The most common and versatile word for fluctuation, especially in economic, financial, or statistical contexts. It implies change that is not necessarily regular.
株価の変動が激しい。
Stock prices are fluctuating wildly.
為替レートの変動に注意してください。
Please pay attention to fluctuations in the exchange rate.
Literally 'up and down', used for fluctuations that involve rises and falls, often in prices, temperatures, or levels.
気温の上下が激しい。
The temperature fluctuates a lot.
物価の上下は経済に影響を与える。
Fluctuations in prices affect the economy.
Focuses on increase and decrease, often used for quantities, numbers, or amounts that go up and down.
人口の増減を調べる。
To investigate fluctuations in population.
A very general word for 'change', but can imply fluctuation in casual contexts. Less precise than 変動.
気分の変わりが激しい。
My mood fluctuates a lot.
To describe physical or abstract undulating movements, oscillations, or variations that are not strictly up-and-down.
Refers to a gentle, often natural fluctuation or swaying, like a flickering flame or a wavering sound. Common in physics and poetic contexts.
ろうそくの炎のゆらぎを見つめる。
Gazing at the fluctuation of the candle flame.
心のゆらぎを感じる。
I feel a fluctuation in my heart/mind.
Literally 'wave', used metaphorically for fluctuations that come in waves, such as trends or cycles.
Also used for physical fluctuations, such as voltage or pressure changes.
To describe changes in mood, feelings, or mental state.
Literally 'ups and downs of mood', a common phrase for emotional fluctuation.
彼は気分の浮き沈みが激しい。
He has severe mood fluctuations.
Refers to emotional disturbance or agitation, a kind of fluctuation in one's mental state.
心の動揺を隠せない。
I can't hide my emotional fluctuation.
Can be used poetically for subtle emotional fluctuations.
To describe random variations in data, measurements, or physical quantities.
In physics and statistics, 揺らぎ (often written in kanji) is the standard term for fluctuation, such as quantum fluctuation or thermal fluctuation.
量子揺らぎは真空でも起こる。
Quantum fluctuation occurs even in a vacuum.
Used in statistics for variation or fluctuation in data.
Refers to dispersion or variability, often used in quality control or statistics for fluctuation in measurements.
変動 is the most general and can refer to any kind of change, not necessarily up and down. 上下 explicitly means up and down movement. 増減 focuses on increase and decrease in quantity. Use 変動 for economic indicators, 上下 for physical levels like temperature, and 増減 for countable changes.
In many contexts, English 'fluctuation' is not directly translated as a noun. Instead, use verb phrases like 変動する, 上下する, or descriptive phrases like 上がったり下がったりする.
株式市場は大きな変動を経験した。
The stock market experienced significant fluctuations.
一日の気温の上下が激しい。
There is a fluctuation in temperature throughout the day.
To ride the wave of economic fluctuation.
電圧の変動を測定する。
To measure voltage fluctuation.
To write about emotional fluctuations in a poem.
データの変動を分析する。
To analyze data fluctuation.
製品の品質にばらつきがある。
There is fluctuation in product quality.