Kyūjitai form of 悪夢 (“nightmare”)

to have a dream

inauspicious dream; nightmare

predictive dream; dream that tells the future

(idiomatic) sweet dreams!

Revealing that the entirety of a fictional story was all part of a dream the protagonist had; the "it was all a dream" ending.

daydream

trance, dreamy state of mind

(rare) a female given name

Synonym of 黄昏 (tasogare, “dusk; twilight”) / Synonym of 黄昏時 (tasogaredoki, “dusk; twilight”)