avoirdupois
noun /ˌævədəˈpɔɪz/, /ˌævwɑːdjuːˈpwɑː/
/ˌævərdəˈpɔɪz/
[uncountable]- the system of weights based on a pound of 16 ounces, widely used in English-speaking countriesWord OriginMiddle English (denoting merchandise sold by weight): from Old French aveir de peis ‘goods of weight’, from aveir ‘to have’ (infinitive used as a noun, from Latin habere) + peis ‘weight’ from an alteration of Latin pensum ‘weight’, from the verb pendere ‘weigh’.