The English word dozen
comes from the old form of the French word douzaine, meaning "a group of twelve" ("Assemblage de choses de même nature au nombre de douze" as defined in the eighth edition of the Dictionnaire de l'Académie française). This French word
is a derivation from the cardinal number douze ("twelve", from Latin duodĕcim) and the collective suffix -aine (from Latin -ēna), a suffix also used to form other words with similar meanings such as quinzaine (a group of fifteen), vingtaine (a group of twenty), centaine (a group of one hundred), etc. These French words have synonymous cognates in Spanish: docena
, quincena, veintena, centena, etc. English dozen, French douzaine and Spanish docena, are also used as indefinite quantifiers to mean "about twelve" or "many" (as in "a dozen times", "dozens of people").
Some historians believe that the base twelve was important because it counts things relating to the marks on the fingers on each hand aside the thumbs. Each finger except for the thumb is divided in three parts, four fingers makes twelve possibilities of counting, and two hands makes possible the accounting of twenty four objects. Using the decimal base for counting only allows ten possibilities with the both hands, one visual option for each finger. This method for accounting was introduced by the Babylonians and its still in use today.