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.
I had a nightmare.
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.
I had a nightmare last night.
That accident was like a nightmare.
Literally 'scary dream'. A more casual, descriptive way to say nightmare, often used in everyday conversation.
A slightly stronger version of 怖い夢, meaning 'terrifying dream'. More literary or emphatic.
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).
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.
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).
The war was a nightmare for the citizens.
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.
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.
The traffic was a nightmare.
Uses 最悪 instead of 悪夢 for a more natural, everyday complaint.
She woke up screaming from a nightmare.
When I was a child, I often had scary dreams and cried.
He woke up from a terrifying dream.
Sleep terror disorder is often seen in children.
It was a nightmarish week.
満員電車は毎朝地獄だ。
The packed train is a nightmare every morning.
The project delay is a nightmare.