The kanji 愚 generally conveys the meaning of "foolishness," "stupidity," "ignorance," or "dull-wittedness." It describes a lack of intelligence, understanding, or common sense. It can also imply a person who is not very wise or clever.

・On-yomi (音読み): グ (gu) ・Kun-yomi (訓読み): おろ（か） (oroka)

⚫︎ 愚か者（おろかもの） Translation: Fool; stupid person ⚫︎ 愚かな考え（おろかなかんがえ） Translation: Foolish idea ⚫︎ 愚民政治（ぐみんせいじ） Translation: Rule by the ignorant; demagogy

The kanji 愚 is a 形声文字 (keisei moji), a phono-semantic compound character. It is composed of two parts: the radical 心（こころ・りっしんべん） (kokoro/risshinben), which means "heart" or "mind," and the phonetic component 禺 (gu). The phonetic component 禺 originally depicted a type of monkey or ape. The combination of the "heart" radical and the phonetic 禺 implies that the quality of 愚 is related to the mind, suggesting a state of being like a monkey, lacking in intelligence or wisdom. The evolution of the character shows that it originally depicted the idea of being simple-minded or lacking intelligence, ultimately leading to its modern meaning.