ominous atmosphere; eerie presence; supernatural aura
Refers to a strange, unsettling atmosphere often associated with ghosts, monsters, or the supernatural. Used in fiction, horror, and everyday descriptions of creepy places.
この廃屋には妖気が漂っている。
An eerie atmosphere hangs over this abandoned house.
彼は妖
He sensed a supernatural presence and stopped in his tracks.
Compound of 妖 (yō, 'bewitching, mysterious, apparition') and 気 (ki, 'spirit, atmosphere, energy'). The exact historical derivation is uncertain, but the combination naturally yields the meaning 'supernatural aura.'