Entry
ガクッ
gaku
This word describes a sudden physical collapse, a sharp drop in numbers, or sudden deep disappointment.
Meaning
Quick Meaning
Literally, it describes joints (like knees or the neck) suddenly giving way due to a loss of strength. Figuratively, it is very commonly used to express sudden, deep emotional disappointment or a sharp, sudden drop in numbers and performance.
- Sudden loss of physical strength (knees giving way).
- Sudden disappointment or discouragement.
- Sharp decline in figures or levels.
Sense Map
Physical Slump
Used when joints suddenly lose support, like knees giving way or a head nodding off to sleep.
膝がガクッとなる
Deep Disappointment
Used when someone feels suddenly shocked, disappointed, or loses all their motivation.
不合格でガクッとくる
Sharp Drop
Used when numbers, sales, or performance levels fall dramatically all of a sudden.
成績がガクッと下がる
Usage Note
How to Use
ガクッとする
Functions as a verb to mean feeling deeply disappointed or losing strength.
ガクッと + verb
Acts as an adverb to describe how something drops, falls, or loses energy suddenly.
カクンと + verb
Used specifically for a joint suddenly bending (often the neck when nodding off).
How to Use
Common Phrases
膝がガクッとなる
knees suddenly give way
ガクッとくる
to feel deeply disappointed / to hit hard emotionally
ガクッと落ちる
to drop sharply (numbers, energy, etc.)
首がカクンとなる
head nods suddenly (when falling asleep)
成績がガクッと下がる
grades drop sharply
Nuance
Context Nuance
| Common Contexts | Nuance | Usage Note |
|---|---|---|
| Body movement | neutral | Only used for joints bending due to sudden loss of strength. |
| Emotions | negative | Describes a sudden hit of disappointment or loss of drive. |
| Statistics | negative | Indicates a sharp and often concerning drop in quality or quantity. |
Similar Words
Comparison Table
| Similar Words | When to Use | Not the Same as | Mini Example |
|---|---|---|---|
がっかり がっかり / similar | Used purely for emotional disappointment without the physical imagery. | Cannot be used for knees giving way or numbers dropping. | がっかりする |
へなへな へなへな / contrast | Used for losing strength completely in a weak, gradual manner. | Unlike ガクッ, which is sudden and sharp. | へなへなと座り込む |
Usage Note
Common Mistakes
Using ガクッ for solid objects breaking into pieces.
Use it for joints bending or levels dropping, not for shattering objects.
Using ガクッ for a slow, gradual decline.
The word strongly implies a sudden, sharp, and noticeable drop.
Examples
Examples
疲れすぎて、立っているのに膝がガクッとなった。
疲れすぎて、立っているのに膝（ひざ）がガクッとなった。
I was so tired that my knees suddenly gave way even though I was standing.
VisualDescribes knees losing their strength.
電車の中で居眠りをして、首がカクンとなった。
電車（でんしゃ）の中（なか）で居眠り（いねむり）をして、首（くび）がカクンとなった。
I nodded off on the train and my head dropped suddenly.
VisualThe variant カクン is often used for the neck dropping when sleepy.
試合に負けたと聞いて、ガクッと気が抜けた。
試合（しあい）に負け（まけ）たと聞いて（きいて）、ガクッと気（き）が抜け（ぬけ）た。
Hearing that we lost the game, all my motivation suddenly dropped.
FigurativeShows a sudden loss of spirit or motivation.
あんなに勉強したのに不合格で、本当にガクッときた。
あんなに勉強（べんきょう）したのに不合格（ふごうかく）で、本当に（ほんとうに）ガクッときた。
Even though I studied so hard, I failed, and it really hit me hard.
FigurativeUsed for a very deep sense of disappointment.
新しい店ができたせいで、この店の売り上げがガクッと落ちた。
新しい（あたらしい）店（みせ）ができたせいで、この店の売り上げ（うりあげ）がガクッと落ちた（おちた）。
Because a new store opened, the sales of this store dropped sharply.
FigurativeShows a drastic drop in numbers.
Similar Words
がっかり
gakkari
To feel disappointed or lose spirit when things don't turn out as expected. がっかり focuses more on the feeling, while ガクッ focuses on the physical or energetic slump caused by disappointment.
へなへな
henahena
Describes something flimsy and easy to bend, or a sudden loss of strength causing one to collapse helplessly. へなへな means losing strength gradually, the opposite of the sudden drop of ガクッ.
Questions
What's the difference between ガクッ and がっかり for disappointment?
がっかり is just the feeling of disappointment, while ガクッ carries the imagery of your shoulders slumping or your body losing energy because of that disappointment.
When should I use カクン?
カクン is almost exclusively used for the sudden downward jerk of the head when someone falls asleep sitting up.
Can ガクッ be used for a sudden increase?
No, it is exclusively used for things going down: losing strength, dropping in numbers, or feeling down.
Source Details
- Entry ID
- 2225490
- Source
- JMdict_english
- Revision
- -
- Review notes
- No special notes
- Active language
- English
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