These words refer to those members of a religion that are set apart from its ordinary followers either by the responsibilities of leadership or by other duties. Clergyman is the generic term for all men set apart in this way; it applies equally well to leaders of Catholic, Protestant and Jewish faiths: cardinals, bishops and other clergyman who met at the Second Vatican Ecumenical Council in Rome; a conference of Lutheran, Presbyterian and Methodist clergymen ; a study group composed of Jewish seminarians and clergymen . Just as clergy contrasts with laity, so clergyman contrasts with laymen to distinguish authorized leaders from ordinary members: a closer relationship between clergymen and laymen. In Christian faiths, the word more specifically indicates someone set apart by ordination, someone who is regularly authorized to preach the gospel and administer sacraments; in addition, it can include in Catholic, Orthodox and Anglican usage anyone who lives in holy orders: priests, monks and other clergymen . At its most general, clergymen may be applied to the leaders of other religions when no more appropriate term from such religions suggests itself.

Cleric may refer, like clergyman , to any member of the clergy, but its use is restricted to the more ritualized or hierarchic faiths. Most specifically it refers to someone distinguished by a tonsure, although it now can suggest any clergyman whose ordination is symbolized by clothing markedly different from that of a layman: a procession of clerics in their colourful regalia. Unlike clergyman , cleric may sometimes give a contemptuous tone when used in criticism, not so much of a church itself, but of church leaders regarded as corrupt: clerics who flout their duties and ignore the needs of the faithful.

Theologian represents a much more specific concept, referring to anyone who formulates or clarifies the doctrines and thinking of a religion; the word may occasionally be applied to members of other than the Western religions: the Hindu theologian Shankara. In any case, the word suggests a learned, philosophical or well-reasoned approach. In theory, theologian can apply to anyone accomplished in such technical discussion, male or female, clergyman or layman. In practice, a theologian has most often been a clergyman of the religion his thinking deals with: the Jewish theologian Maimonides who influence the thought of St. Thomas Aquinas. While the word suggests an official or orthodox approach, this is not always necessarily implied in practice: the theologian Arius whose doctrines were declared heretical in the 4th century A.D.; recent theologians who formulated the controversial "God-is-dead" theory. While divine may refer in a general way to a clergyman , particularly one highly placed, the word at its most specific refers to a theologian whose doctrines are accepted and honoured by his religion: church divines of the early centuries whose main task was to combat such heresies as Arianism and manicheanism.

Ecclesiastic refers to any clergyman in a church with an emphasis on a clergy arranged in a ranked and structured hierarchy, thus applying particularly to Catholic, Orthodox and such Protestant churches as the Anglican: an ecclesiastic in the Church of England. Prelate more specifically refers to an ecclesiastic of superior rank and authority, as a bishop or cardinal, or to a dignitary of a particular church. This word, even more than cleric , can be given a negative ring by someone critical of the clergy: prelates who grow fat and rich while the people starve.

While religious is restricted in reference to someone living in holy orders, usually in the context of the more formalized faiths, the word is unique here in that it applies equally well both to a man or woman in such orders: a girl who wished to become a religious and retire to the sheltered life of the convent.

• Not always mandatory for parish priests, celibacy nevertheless was always in force for the religious , both monks and nuns.