The kanji 腐 primarily conveys the idea of decay, rot, decomposition, or putrefaction. It describes the process of something breaking down or becoming spoiled, often due to the action of microorganisms or other environmental factors. This kanji suggests a state of decline or deterioration from an original, better condition.

・On-yomi (音読み): フ (fu) ・Kun-yomi (訓読み): くさ(る) (kusa(ru)) - to rot, to decay くさ(れる) (kusa(reru)) - to be rotten, to decay

⚫︎食べ物が腐る Translation: Food spoils/rots. ⚫︎精神が腐敗する Translation: The spirit/mind decays. ⚫︎腐心する Translation: To rack one's brains; to make a great effort.

The kanji 腐 is a 形声文字 (keisei moji), a phono-semantic compound character. The character is composed of the radical 肉(ni-kuzukuri) meaning "flesh" or "meat" on the left, and 付(fu) on the right, which provides a phonetic component. This phonetic component gives a clue about the sound and meaning. The combination of "flesh/meat" and "fu" (sound) suggests the idea of flesh undergoing decomposition, thereby giving the meaning of "to rot" or "decay." This reflects an early understanding of the connection between the deterioration of organic matter and the processes involved in spoilage.