Avoirdupois weight is the system we use whenever we measure a grain, dram (27.3 grains), ounce (16 drams), or pound (16 ounces).
What is avoirdupois weight?

Avoirdupois weight is the system we use whenever we measure a grain, dram (27.3 grains), ounce (16 drams), or pound (16 ounces).