Almost wander into office of cathedral official (7)
I believe the answer is:
provost
'cathedral official' is the definition.
(type of church official)
'almost wander into office of' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'wander' becomes 'rove' (synonyms).
'into' is an insertion indicator.
'office of' becomes 'post' (I can't justify this - if you can you should believe this answer much more).
'rove' with its final letter taken off is 'rov'.
'rov' going into 'post' is 'PROVOST'.
(Other definitions for provost that I've seen before include "University college head" , "A college head; a mil. policeman" , "College head - Scots mayor" , "Cathedral dignitary" , "The head of certain colleges like Trinity, Dublin" .)