From Longman Dictionary of Contemporary Englishavoirdupoisav‧oir‧du‧pois /ˌævwɑːdjuːˈpwɑː, ˌævədəˈpɔɪz $ ˌævərdəˈpɔɪz/ noun [uncountable] TMthe system of weighing things that uses the standard measures of the ounce, pound, and ton → metric system
Examples from the Corpus
avoirdupois• There are 27.34 grains in one dram, 16 drams to one ounce and 16 ounces to one avoirdupois pound.From Longman Business Dictionaryavoirdupoisav‧oir‧du‧pois /ˌævədəˈpɔɪz, ˌævwɑːdjuːˈpwɑːˌævərdəˈpɔɪz/ noun [uncountable] a system of weighing things used in the UK and US, based on the standard measures of the OUNCE, POUND, and TON, which is being replaced in the UK by the METRIC SYSTEMThere are 16 ounces to one avoirdupois pound.Origin avoirdupois (1300-1400) Old French avoir de pois “goods of weight” 