The kanji 怪 primarily conveys the idea of something unusual, strange, or mysterious. It often implies a sense of peculiarity, abnormality, or even something supernatural. It suggests something that deviates from the norm or is difficult to understand. It can also imply suspicion or doubt.

・On-yomi (音読み): カイ ・Kun-yomi (訓読み): あや-しい (ayashii)

⚫︎ 怪しい人(ayashii hito) Translation: Suspicious person ⚫︎ 怪奇現象(kaiki genshō) Translation: Strange phenomenon ⚫︎ 怪物(kaibutsu) Translation: Monster

The kanji 怪 is a phono-semantic compound (形声文字). The left side is the radical 心(kokoro), meaning "heart" or "mind", which acts as the semantic component (meaning part), and the right side is the phonetic component 圭(kei), which provides the sound. The combination suggests something that affects the mind or is related to something unusual or strange. The character evolved over time, with the meaning rooted in the idea of the unusual or peculiar.