Admit to a certain order (6)

I believe the answer is:

ordain

I'm a little stuck... Click here to teach me more about this clue!

'order' is the definition.
(I know that order can be written as ordain)

I can't explain the rest of the clue.

(Other definitions for ordain that I've seen before include "Make someone a clergyman" , "Install as priest" , "Decree and admit to holy orders" , "Invest with ministerial authority" , "Initiate as priest" .)

I've seen this clue in The Irish News.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.