The word "愚笨" is formed by combining two characters: "愚" consists of "禺" (historically referring to a monkey or mythical creature) above "心" (heart/mind), implying a foolish mind, while "笨" consists of "竹" (bamboo) above "本" (root), originally denoting the soft, inner part of bamboo and later extended to mean stupid. Together, these characters semantically reinforce each other to convey the meaning of foolishness or stupidity.