Translation guide
A nightmare is a frightening or very unpleasant dream. In Japanese, the most common word is 悪夢 (あくむ), but there are other expressions for bad dreams, night terrors, and figurative 'nightmarish' situations.
To refer to a bad dream that causes fear, anxiety, or distress during sleep.
The standard word for 'nightmare' in Japanese. It can be used for both literal bad dreams and metaphorical nightmarish experiences.
昨夜、悪夢を見た。
I had a nightmare last night.
その事故はまるで悪夢のようだった。
That accident was like a nightmare.
Literally 'scary dream'. A more casual, descriptive way to say nightmare, often used in everyday conversation.
子供の頃、よく怖い夢を見て泣いていた。
When I was a child, I often had scary dreams and cried.
A slightly stronger version of 怖い夢, meaning 'terrifying dream'. More literary or emphatic.
彼は恐ろしい夢から目が覚めた。
He woke up from a terrifying dream.
Refers to a nightmare or sleep paralysis where one feels oppressed or cries out. Often used in the phrase 魘される (to have a nightmare).
夜中に魘されて叫んでしまった。
I had a nightmare in the middle of the night and screamed.
To refer to a sleep disorder involving intense fear, screaming, and thrashing while still asleep, distinct from a typical nightmare.
The medical term for 'night terror' or 'sleep terror disorder'. Used in clinical contexts.
子供の夜驚症は成長とともに治ることが多い。
Night terrors in children often resolve as they grow.
A more formal or alternative medical term for night terror disorder.
睡眠時驚愕症は小児に多く見られる。
Sleep terror disorder is often seen in children.
To describe a situation or experience that is extremely difficult, distressing, or seemingly endless.
Also used metaphorically, just like in English. Common in phrases like 悪夢のような (nightmarish).
その戦争は国民にとって悪夢だった。
The war was a nightmare for the citizens.
悪夢のような一週間だった。
It was a nightmarish week.
Literally 'hell'. Used hyperbolically to describe an unbearable situation, similar to 'nightmare' in English.
Means 'the worst situation'. A straightforward way to express that something is a nightmare without using figurative language.
プロジェクトの遅れは最悪の状況だ。
The project delay is a nightmare.
悪夢 is the direct equivalent of 'nightmare' and can be used in both literal and figurative senses. 怖い夢 is more colloquial and specifically refers to a scary dream, not a metaphorical nightmare. Use 怖い夢 when talking casually about a bad dream you had, and 悪夢 for more serious or literary contexts.
While 悪夢 can be used figuratively, it carries a strong sense of horror or lasting trauma. For everyday annoyances (like a bad day at work), 最悪 or 大変 might be more appropriate than 悪夢.
渋滞がひどくて最悪だった。
The traffic was a nightmare.
Uses 最悪 instead of 悪夢 for a more natural, everyday complaint.
彼女は悪夢にうなされて叫びながら目を覚ました。
She woke up screaming from a nightmare.
満員電車は毎朝地獄だ。
The packed train is a nightmare every morning.