One of those at The Abbey is popular with the foreign women related by marriage (7-2-3)
I believe the answer is:
brother-in-law
'one of those at the abbey' is the definition.
I can't judge whether this definition defines the answer.
'popular with the foreign women related by marriage' is the wordplay.
I cannot quite see how this works, but
'popular' could be 'in' ('in' can mean trendy) and 'in' is present in the answer.
'with' could be 'w' (abbreviation) and 'w' is found in the answer.
'related' could be 'brother' (similar in meaning) and 'brother' is found in the answer.
'the foreign' could be 'la' and 'la' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'is' acts as a link.
Can you help me to learn more?
(Other definitions for brother-in-law that I've seen before include "Relative by marriage" , "Family member by marriage" .)