The name given to certain of the ancient Chinese round coins from the inscription on them, Pan Liang, or Half Ounce. This style of coin was issued during the Ch'in and Han dynasties, circa B.C. 220-86. It originally was of good weight, but gradually so deteriorated that the coinage was abolished.
Source: Frey's Dictionary (American Journal of Numismatics, Vol. 50, 1916)