They've cornered a part of Westminster Abbey (5)
I believe the answer is:
poets
'they've cornered a part' is the definition.
I can't judge whether this definition defines the answer.
'of westminster abbey' is the wordplay.
I cannot really see how this works, but
'of' could be 'o' and 'o' is found in the answer.
The remaining letters 'pets' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for poets that I've seen before include "Verse writers" , "Estop (anag.)" , "bridges, for example (but extra capital is needed)" , "Burns" , "Heaney and Muldoon" .)