The word 不齿 is formed by combining the character 不, meaning "not", with 齿, which in this context derives from its classical usage meaning "to mention" or "to speak of" someone alongside others, as teeth are arranged in order. Thus, 不齿 literally means "not to mention" and semantically conveys the act of refusing to associate with or speak of someone due to contempt, indicating they are unworthy of consideration.