nightmare
🇺🇸
/ˈnaɪtmer/
🇬🇧
/ˈnaɪtmeə(r)/
a scary or bad dream
She had a nightmare about being lost in a dark forest.
彼女は暗い森で迷う悪夢を見ました。
a very scary or hard experience
The traffic jam was a nightmare that made us very late.
交通渋滞は私たちをとても遅らせた悪夢のような体験でした。