A dream: the images or events experienced during sleep; metaphorically, hopes or ambitions for the future.
昨夜、不思議な夢を見た。
I had a strange dream last night.
彼女は医者になるという夢を持っている。
She has a dream of becoming a doctor.
朝起きて、夢の内容を日記に書いた。
I woke up and wrote the contents of my dream in a diary.