noun
mysterious occurrence; strange phenomenon
Refers to eerie, supernatural, or inexplicable events, often with a literary or traditional feel. Not an everyday word for minor oddities.
その村では古くから妖異が語り継がれている。
Mysterious occurrences have been passed down in that village since ancient times.
彼は妖異を題材にした小説を書いている。
He is writing a novel based on strange phenomena.
Composed of 妖 (bewitching, mysterious) and 異 (strange, unusual). The exact historical derivation is uncertain, but the combination naturally yields the meaning 'mysterious and strange occurrence'.