Priest is the English word that originated from the Greek word πρεσβυτερος (presbyteros), which means elder. (Note the progression from presbyter to prester to priest.) Originally, this was the normal word for Christian clergy. Over time it took over the meaning of ’ιερευς (hiereus or hierarch) and was extended by way of analogy to Jewish and then pagan clergy. Some groups avoid priest as if it were pagan, when it is in fact entirely Christian and scriptural in origin. The Greek word for a temple functionary is hierarch.

In many New Testament translations, the word priest is used to translate both presbyter and hierarch, which can confuse the reader. It gives the false impression that the Church has no clergy or that all Christians are clergy. The Greek New Testament teaches a hierarchy of all believers, not a presbytery of all believers—meaning that all Christians have direct access to God, but not all have administrative, supervisory, or sacramental duties in the Church. (See 1 Peter 2:1-10 in the original Greek.)

Roman Catholic priests must be unmarried at the time of their ordination and they must remain that way. In the Eastern Church, a priest must remain in the state in which he was ordained. If he was single when he was ordained a priest, he must remain unmarried. If he was married when he was ordained a priest, he may remained married, but he is not permitted to remarry if he is widowed. Anglican and Lutheran priests can marry after ordination. (Lutheran clergy in Scandinavia and the Baltic countries are called priests.) If an Anglican or eastern priest becomes a Roman Catholic priest, his marital status is not a barrier. This means that there are a few married priests in the Roman Catholic Church.

Priests, that is, regular ordained clergy, wear black clericals.