The word 愚钝 is formed by combining 愚, meaning "foolish", which is composed of 禺 (suggesting dullness) and 心 (heart), indicating a dull mind, with 钝, meaning "blunt" or "dull", composed of 金 (metal) and 屯 (implying difficulty), denoting a lack of sharpness; together they convey the meaning of being foolish and slow-witted.