In its etymological sense this expression signifies every person who forms a part of the external and visible society which constitutes the Church, and who has not been canonically expelled therefrom. But the expression is rarely used in this sense; customarily it indicates persons whom a special tie connects with the Church, either because they have received ecclesiastical tonsure, minor, or higher orders, and are a fortiori invested with a power of jurisdiction; or because they have taken vows in a religious order or congregation approved by the Church. This more intimate union with the Church involves particular duties which are not incumbent on the general faithful (see CLERIC).
SCHERER, Handbüch des Kirchenrechts, I (Graz, 1886), 309-12.