Members of the family in a religious order (8)
I believe the answer is:
brothers
'members' is the definition.
(I know this)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for brothers that I've seen before include "Siblings (in arms or in law?)" , "See 5" , "Fraternal relatives" , "Male siblings" , "Brethren" .)