The word 来龙去脉 is formed by combining four characters: 来 (coming), 龙 (dragon), 去 (going), and 脉 (vein). It originates from traditional Chinese geomancy, where 来龙 refers to the incoming dragon symbolizing the origin or starting point, and 去脉 refers to the outgoing vein symbolizing the subsequent course or development; together they literally depict the entire topographic flow from source to end, which metaphorically conveys the complete sequence or cause and effect of a matter.