The word 顾客 (gùkè) is formed by combining two characters, each contributing a core idea to create the composite meaning. The first character, 顾 (gù), originally meant "to look back" or "to turn one's head to look", which evolved to carry the sense of "to attend to", "to visit", or "to patronize". The second character, 客 (kè), means "guest" or "visitor". When joined, the concept essentially becomes "a visiting patron" or "a guest who attends (to a business)", which perfectly encapsulates the modern meaning of "customer".