The word "不逞之徒" is formed by sequentially combining the characters "不" (meaning 'not'), "逞" (meaning 'to succeed' or 'to achieve one's desire'), "之" (a possessive particle functioning as 'of'), and "徒" (meaning 'person' or 'follower'). This structure creates a literal meaning of "a person who does not achieve their desires", which semantically narrows to refer to discontented individuals or troublemakers acting from frustration.