(Lat. abbas; from Chaldee אִבָּא, the father), the head or superior of an abbey of monks.
1. The title was originally given to every monk, but after the sixth century was restricted to the heads of religious houses. At a later period the title was not confined to the superiors of monasteries, but was also given to the superiors of other institutions (as abbas curie, palatii, scholarum, etc.), while, on the other hand, several other terms, as provost, prior, guardian, major, rector, etc., were adopted to designate the superiors of the convents of the several orders. The Greek Church uses generally the term archimandrite (q.v.). The name abbot was especially retained by the order of the Benedictines, and its branches, the Cistercians, Bernhardines, Trappists, Grandmontanes, Praemonstratenses. But the congregation of Clugny (q.v.) reserved the title abbot to the superior of the principal monastery, calling those of the other monasteries coabbates and proabbates. The Abbot of Monte-Cassino assumed the title abbas abbatum. A number of religious orders are governed by an abbot-general, e.g. (according to the Notizie per 'Anno 1859, the Official Roman Almanac), the regular canons of Lateran, the Camaldulenses, the Trappists, the Olivetans, the (Oriental) order of St. Antonius, and the Basilians. Regular abbots are those who wear the religious habit, and actually preside over an abbey, both in spiritual and temporal matters. Secular abbots are priests who enjoy the benefices, but employ a vicar (q.v.) to discharge its duties. Lay abbots are laymen to whom the revenues of abbeys are given by princes or patrons. Field abbots (abbates castrensus) are regular abbots appointed for army service. Arch abbot is the title of the abbot of St. Martini, in Hungary. The abbots are, in general, subject to the jurisdiction of the diocesan bishop, but formerly some were exempt, and had even a kind of episcopal jurisdiction (jurisdictio quasi episcopalis), together with the right of wearing episcopal insignia (mitred abbots, abbates mitrati). Some, as the abbot of St. Maurice, in Switzerland, have even a small territory. Abbots with episcopal jurisdiction have the right of taking part in general councils, and the right of voting in provincial synods. The privileges and duties of abbots are determined by the rules of the order to which they belong, as well as by canonical regulations.
The commendatory abbots (abbates commendatarii; Fr. abbes commendataires), in France and England, were secular ecclesiastics, to whom abbeys were given in commendam, who enjoyed a portion of the revenues, together with certain honors, but without jurisdiction over the inmates of the abbeys. This became latterly so common that most abbeys were thus held perpetually in commendam. In England many abbots, among other privileges, had the right of sitting in the House of Lords. According to Fuller (Ch. Hist. b. 6, p. 292, ed. 1655), there were sixty-four abbots and thirty-six priors, besides the Master of the Temple summoned to Parliament, which he terms "a jolly number." Edward III reduced them to twenty-six. In Germany, ten prince-abbots (of Fulda, Corvey, etc.) were members of the German Diet till 1803. See Bingham, Orig. Eccles. b. 7, ch. 3; Conc. Trident. Sess. 25, and, for full details, Martene, De Ant. Monach. Rit. lib. 5. The forms for the benediction of abbots (i. q. inauguration) are given in Boissonnet, Dict. des Ceremonies, 1:22 sq.
2. The title of Abbot is still used in some Protestant countries. In Germany it is sometimes conferred upon divines, especially if they enjoy the revenues of former abbeys. Thus the late Professor Lucke of Gottingen was an abbot.