Regular clergy
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
In old English law
Monks who lived secundum regulas (according to the rules) of their respective houses or societies were so denominated, in contradistinction to the parochial clergy, who performed their ministry in the world, tn seculo, and who from thence were called "secular" clergy.
1 Chit. Bl. 387, note.