Dean (Lat. decanus, chief of ten; old Fr. deien; mod. Fr. doyen), a title given to certain persons who, in ecclesiastical or lay bodies, are first either in dignity or in seniority. The various etymologies of this word, as given in Du Cange's Glossarium, show that the decani were at the introduction of Christianity minor officers of the civil, military, and ecclesiastical administrations of the Roman empire. In the army a decanus had charge of ten men, while the centurion commanded ten decanice. In the judicial organization under the emperors, there were decani or petty judges in each hamlet or country district, which also bore the name of decania: decani.... minores judices qui per decanias jus dicebant. In the imperial court of Constantinople, the decani were inferior officers or ushers. The name passed into the church with similar functions. In the East, especially in the churches of Constantinople, the was a lay officer or beadle, having care of the church decoration and ceremonial; he assigned each clergyman his place in the public functions, and distributed to each his stipend. In ancient monasteries the monks were distributed into decaniae, over each of which a decanus or dean presided, who superintended the manual labors and devotional exercises of his ten, and rendered an account thereof to the abbot. In some at least of the ancient female monasteries, officers with a corresponding denomination existed. It was retained in western Europe by the church, the great schools, the guilds of trades, the learned professions, scientific and literary academies, and by municipal bodies. In the church, the word dean was more especially applied either to the heads of chapters in collegiate churches, or to archpriests in the country who had the superintendence of the parishes and clergy of the deaneries or districts into which each diocese was divided, and who thence were called "rural deans," in contradistinction from "deans of cathedral churches" or "deans of peculiars," i. e., of collegiates that were not cathedrals, both of which classes were generally confined to cities.

In France and other continental countries the same ecclesiastical division and office existed under different names. In some French dioceses the rural dean is called archi-pretre, and his deanery archipretre; in others he is called cure-doyen, or simply doyen. In cities and large towns there are also archi-pretres and cures-doyens. In Italy rural deans were unknown before the 15th century, probably on account of the great multiplicity of episcopal sees and the consequent narrow limits of each diocese. In Ireland rural deans are to be found everywhere among the Catholic clergy. - The denomination "dean" in the English church is exclusively applied either to deans of collegiate churches, whether these churches actually have chapters, or had them before the reformation. In universities a-dean is sometimes head of a house or college, and sometimes only charged with the maintenance of religious discipline. The various faculties in universities, such as theology, medicine, and law, have their deans, who are generally so by seniority or priority of admission. Such is the case also in the college of cardinals, whose dean is the oldest cardinal bishop by promotion.

Thus too the French have their doyen de l'academie francaise, doyen des avocats, and doyen des marechaux de France. In every country the resident diplomatic body has its dean. In all Christian countries during the middle ages the various trades' corporations or guilds had their deans. In the old French parlements, the oldest maitre des requites was called doyen des doyens. - Toward the end of the 8th century we find the first authentic mention made of female chapters or canoness-es, who were either regular canonesses, following the rule of St. Augustine, or secular, and bound by no permanent religious vows. Such bodies became quite numerous in course of time both in France and Germany, and were composed almost exclusively of ladies of royal, princely, or noble birth. The most famous in France was the house of Remiremont. In France the appellation of doyenne was in many instances given to the heads of such chapters; and the phrase elire la doyenne is frequently met with in old historians.