CUSTOM (from O. Fr. custume, costume or coustume; Low Lat. costuma, a shortened form of consuetude), in general, a habit or practice. Thus a tradesman calls those who deal with him his " customers," and the trade resulting as their " custom." The word is also used for a toll or tax levied upon goods; there was at one time a distinction between the tax on goods exported or imported, termed magna custuma (the great custom), and that on goods taken to market within the realm, termed pari'a custuma (the little custom), but the word is now used in this sense only in the plural, to signify the duties levied upon imported goods. It is also used as a name for that department of the public service which is employed in levying the duty.
In law, such long-continued usage as has by common consent become a rule of conduct is termed custom. Jessd, M. R. (Hammerton v. Honey, 24 W. R. 603), has defined it as " local common law. It is common law because it is not statute law; it is local law because it is the law of a particular place, as distinguished from the general common law. Local common law is the law of the country (i.e. particular place) as it existed before the time of legal memory." There has been much discussion among jurists as to whether custom can properly be reckoned a source of law (see JURISPRUDENCE); As to the distinction between prescription (which is a personal claim) and custom, see PRESCRIPTION. The adoption of local customs by the judiciary has undoubtedly been the origin of a great portion of the English common law. Blackstone divides custom into (i) general, which is the common law properly so called, and (2) particular, which affects only the inhabitants of particular districts. The requisites necessary to make a particular custom good are: (i) it must have been used so long that the memory of man runneth not to the contrary; (2) it must have been continued, and (3) enjoyed peaceably; (4) it must be reasonable, and (5) certain; (6) it must be compulsory, and not left to the option of every man whether he will use it or no; (7) it must be consistent with other customs, for one custom cannot be set up in opposition to another. Customs may be of various kinds, for example, customs of merchants, customs of a certain district (such as gavelkind and borough English), customs of a particular manor, etc. The word custom is also generally employed for the usage of a particular trade or market; for a trade custom to be established tothe satisfaction of the law it must be a uniform and universal practice so well defined and recognized that contracting parties must be assumed to have had it in their minds when they contracted (Russell, C. J., Fox-Bourne v. Vernon, 10 Times Rep. 649).
In the history of France the term " custom " was given to those special usages of different districts which had grown up into a body of local law, as the " custom of Paris," the " custom of Normandy " (see FRANCE : Law and Institutions),
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)