avoirdupois in British English
or avoirdupois weight (ˌævədəˈpɔɪz, ˌævwɑːdjuːˈpwɑː)
nouna system of weights used in many English-speaking countries. It is based on the pound, which contains 16 ounces or 7000 grains. 100 pounds (US) or 112 pounds (Brit) is equal to 1 hundredweight and 20 hundredweights equals 1 ton
Abbreviation: avdp, avoir