These words refer to a religion’s clergy – that is, those who lead a congregation in worship or belong to teaching or monastic orders. Minister refers exclusively to a Protestant clergyman who has been authorized to administer sacraments and conduct religious services. Pastor is used in Australia and New Zealand in reference to a minister , although not so commonly as in the United States. In a general, informal sense, it is used by all churches, as in "he is a good pastor ," i.e. a good shepherd to his flock. The word is an official title in several denominations, notably the Church of Christ, Lutheran churches and some Baptist churches.

Preacher and reverend also apply to the clergy of some Protestant faiths. Preacher is much more informal than the previous words and means simply a man who preaches or delivers a sermon; it has nothing to do with rank or title.

• The preacher on Sunday will be the Rev. John Smith; The sedate congregation was clearly displeased by this fire-and-brimstone preacher .

Reverend may properly appear as part of a title or courtesy phrase: the Reverend Dr. Jones. It may appear in other set phrases before a name, such as the Right Reverend or the Most Reverend . It is incorrect when any such title is shortened to the one word alone: Reverend Johns. Use of the word as a noun, e.g., I shall phone the reverend , is also improper, although some people tend to address a minister directly as Reverend .

In Catholic and Eastern Orthodox churches, priest designates a member of the clergy who has been authorized to administer the sacraments; if he has a parish in his charge he may be referred to as a pastor , but in any case he may be addressed as father : Father Brown.

• Good morning, Father .

The word is never used with an article, however, except to refer to the early founders of the church or, collectively, to its leaders: the church fathers who fought heresies on the one hand and persecution on the other; a meeting of the fathers of the church.

In these same faiths, monk refers to a man in holy orders, particularly monastic ones; such a man may or may not be a priest as well. If so, he would be referred to as father ; if not, he would be referred to as brother . Unlike father , brother may well be used with a definite article: the poet who became a brother in a Trappist monastery. Monk and priest both may refer to comparable roles in other religions of the world, past or present: a Buddhist monk ; a Druid priest ; a Tibetan priest .