The Chinese word 敲竹杠 is formed from the characters 敲 (to knock), 竹 (bamboo), and 杠 (pole), directly referencing a historical practice where merchants, such as those in opium trades or street vendors, would knock on hollow bamboo poles used to transport goods or conceal money to assess hidden wealth, thereby forcibly extracting higher payments from customers, which led to the term's figurative meaning of overcharging or extortion.