TRAFFIC, properly the interchange or passing of goods or merchandise between persons, communities or countries, commerce or trade. The term in current usage is chiefly applied collectively to the goods, passengers, vehicles and vessels passing to and fro over the streets, roads, sea, rivers, canals, railways, &c.
The origin of the word is obscure. It occurs in Fr. trafique, and trafiquer, Ital. traffico, trafficare, Sp. trafago, trafagar. Du Cange (Gloss. Med. el Inf. Lot.) quotes the use of traffigare from a treaty between Milan and Venice of 1380, and gives other variants of the word in medieval Latin. There is a medieval Latin word transfeeator, an explorer, spy, investigator (see Du Cange, op. cit., s.v.) which occurs as early as 1243, and is stated to be from transfegare, a corruption of transfretare, to cross over the sea (trans, across, fretum, gulf, strait, channel). Diez (Etymologisches Worterbuch der romanischen Sprachen) connects the word with Port, trasfegar, to decant, which he traces to Late Lat. vicare, to exchange, Lat. vicis, change, turn. A suggestion (Athenaeum, app. 7, 1900) has been made that it is to be referred to a late Hebrew corruption (traffik) of Gr. Tpoira'Uds, pertaining to a trophy, applied to a silver coin with the figure of victory upon it and termed in Latin victoriatus.