Rotter does away with king in cathedral area (4)
I believe the answer is:
nave
'cathedral area' is the definition.
(area of a cathedral)
'rotter does away with king' is the wordplay.
'rotter' becomes 'knave' (I've seen this before).
'does away with' is a deletion indicator (to do away with can mean to remove).
'king' becomes 'k'.
'knave' with 'k' taken out is 'NAVE'.
'in' is the link.
(Other definitions for nave that I've seen before include "Central area in a church" , "Part of a church sounds roguish" , "The hub of a wheel, or body of church" , "Take no risks" , "Central space in church" .)