1.
evil spirit, vengeful ghost, supernatural being
A malevolent spirit or supernatural entity believed to possess or afflict people, causing illness or misfortune. A concept rooted in classical Japanese literature and folklore.
Writing
Written as 物の怪. The 怪 means "strange/mysterious thing."
Cultural note
A key concept in classical Japanese literature, especially in 源氏物語 (The Tale of Genji), where 物の怪 possesses and torments characters. In the Heian period, illness and psychological distress were often attributed to 物の怪.
Modern usage
Widely known today through Studio Ghibli's film 「もののけ姫」 (Princess Mononoke, 1997). In modern usage, the word evokes an atmospheric, folkloric sense of the supernatural.