The avoirdupois (IPAEng|ˌævərdəˈpɔɪz; French IPA2|avwaʀdypwɑ) system is a system of weights (or, properly, mass) based on a pound of sixteen ounces. It is the everyday system of weight used in the United States. It is still widely used by many people in Canada and the United Kingdom despite the official adoption of the metric system, including the compulsory introduction of metric units in shops. It is consideredFact|date=May 2007 more modern than the alternative troy or apothecary or the medieval English mercantile and Tower systems.

History of the term

The word "avoirdupois" is from French and Middle English (Anglo-French) "avoir de pois", "goods of weight" or "goods sold by weight", from Old French "aveir de peis", literally "goods of weight" (Old French "aveir", "property, goods", also "to have", comes from the Latin "habere", "to have, to hold, to possess property"; "de" = "from", cf. Latin; "peis" = "weight", from Latin "pensum"). This term originally referred to a class of merchandise: "aveir de peis", "goods of weight", things that were sold in bulk and were weighed on large steelyards or balances. Only later did it become identified with a particular system of units used to weigh such merchandise. The imaginative orthography of the day and the passage of the term through a series of languages (Latin, Anglo-French and English) has left many variants of the term, such as "haberty-poie" and "haber de peyse". (The Norman "peis" became the Parisian "pois". In the 17th century "de" was replaced with "du".)

Original forms

These are the units in their original French forms:


In the avoirdupois system, all units are multiples or fractions of the pound, which is now defined as 0.45359237 kg in most of the English-speaking world since 1959. (See the Mendenhall Order for references.)

Due to the ambiguous meanings of "weight" as referring to both mass and force, it is sometimes erroneously asserted that the pound is only a unit of force. However, as defined above the pound is a unit of mass, which agrees with common usage. Also see pound-force and pound-mass.

ee also

* French units of measurement
* Apothecaries' system
* Imperial unit
* Troy weight
* United States customary units


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Look at other dictionaries:

  • Avoirdupois — Avoirdupois, seit 1855 in England eingeführte Einheit des Handelsgewichtes, auch in den meisten englischen Kolonien und den Vereinigten Staaten gebräuchlich. Es trat an die Stelle des Troygewichtes (s.d.), das aber heute noch neben ihm als… …   Lexikon der gesamten Technik

  • Avoirdupois — Av oir*du*pois ([a^]v [ e]r*d[ u]*poiz ), n. & a. [OE. aver de peis, goods of weight, where peis is fr. OF. peis weight, F. poids, L. pensum. See {Aver}, n., and {Poise}, n.] 1. Goods sold by weight. [Obs.] [1913 Webster] 2. Avoirdupois weight.… …   The Collaborative International Dictionary of English

  • Avoirdupois — [ˌævədəˈpɔɪz, ˌævwɑːdjuːˈpwɑː] ist ein angloamerikanisches Maßsystem für Masse, das auf einem Pfund bestehend aus 16 Unzen basiert. Es handelt sich hierbei um ein traditionelles Handelsgewicht und wird nicht für Edelmetalle und Arzneien verwendet …   Deutsch Wikipedia

  • avoirdupois — ● avoirdupois ou averdepois nom masculin (ancien français aveir de peis, avoir du poids) Système de poids appliqué en Grande Bretagne et aux États Unis dans lequel un pound vaut 16 ounces (453,592 428 g). avoirdupoi(d)s [avwaʀdypwa] n. m. ÉTYM.… …   Encyclopédie Universelle

  • avoirdupois — av‧oir‧du‧pois [ˌævədəˈpɔɪz, ˌævwɑːdjuːˈpwɑː ǁ ˌævərdəˈpɔɪz] 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 system …   Financial and business terms

  • avoirdupois — [av΄ər də poiz′] n. [ME aver de poiz < OFr aveir de peis < aveir, goods (< L habere, to have) + de (< L de), of + peis (< L pensum), weight] 1. AVOIRDUPOIS WEIGHT ☆ 2. Informal heaviness or weight, esp. of a person …   English World dictionary

  • Avoirdupois — (spr. awūardüpūa oder äwwerdjūpeus, abgekürzt avdp.), engl. Handelsgewicht, auch in den meisten englischen Kolonien und den Vereinigten Staaten für alle Waren außer feinern Wägungen, wozu das Troygewicht (s. d.) dient. Anstatt des letztern ward… …   Meyers Großes Konversations-Lexikon

  • Avoirdupois — (frz. awŏahrdüpŏá), Beiname des engl. Handelsgewichts, im Gegensatz zum Troygewicht (s.d.). Das A. Pfund zu 7680 A. Grän = 7000 Troygrän = 453,59 g; der Stone (Stein) hat 14, das Quarter 28, der Hundredweight oder Centweight (Zentner) 112, in… …   Kleines Konversations-Lexikon

  • avoirdupois — (n.) 1650s, misspelling of M.E. avoir de peise (c.1300), from O.Fr. avoir de pois goods of weight, from aveir property, goods (noun use of aveir have ) + peis weight, from L. pensum, neut. of pendere to weigh (see PENDANT (Cf. pendant) …   Etymology dictionary

  • avoirdupois — ► NOUN ▪ a system of weights based on a pound of 16 ounces or 7,000 grains. Compare with TROY(Cf. ↑troy). ORIGIN from Old French aveir de peis goods of weight …   English terms dictionary

  • Avoirdupois — El sistema de pesos avoirdupois (/ˌævərdəpɔɪz/, pronunciación francesa: [avwaʁdypwɑ]) es un sistema de pesos (o, más propiamente, de masas) establecido en base a la libra de 16 onzas. Es el sistema de pesos usado habitualmente en los Estados… …   Wikipedia Español

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