A cold church with small southern entrance (6)
I believe the answer is:
access
'entrance' is the definition.
(I've seen this in another clue)
'a cold church with small southern' is the wordplay.
'cold' becomes 'c' (eg on taps).
'church' becomes 'CE' (abbreviation for Church of England).
'with' is a charade indicator (letters next to each other).
'small' becomes 's' (abbreviation - e.g. clothes size).
'southern' becomes 's' (abbreviation).
'a'+'c'+'ce'+'s'+'s'='ACCESS'
(Other definitions for access that I've seen before include "Entrance or passage" , "Means or way of gaining entry" , "OK to go in" , "Entr" , "The right to use something or see someone" .)