The word 纪律 is formed by combining two characters, each contributing a layer of meaning to create a unified concept. 纪 (jì) originally referred to the separate strands of silk in a thread, evolving to signify recording, order, and systems. 律 (lǜ) initially meant the pitch pipes used to set musical standards, extending to denote laws, rules, and statutes. When fused, 纪律 metaphorically represents the binding together of individual strands of conduct (纪) according to a fixed, authoritative standard (律), forming the complete idea of disciplined, rule-governed order within a group or system.