[German Version]

(sacerdos saecularis), the opposite of a religious priest, who is a member of a religious order, order being understood in the broad sense as a generic term for religious institutes (orders [Orders, Catholic] ¶ in the strict sense and congregations), secular institutes, and societies of apostolic life. A secular priest is therefore any priest who does not belong to one of these groups, regardless of whether he is incardinated into it (Incardination).

Peter Neuner