Publicity for church in part of Africa (4)
I believe the answer is:
chad
'part of africa' is the definition.
('Chad' is part of 'africa')
'publicity for church' is the wordplay.
'publicity' becomes 'ad' (advert).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'church' becomes 'ch' (common abbreviation).
'ad' put after 'ch' is 'CHAD'.
'in' is the link.
(Other definitions for chad that I've seen before include "Fish" , "African country south of Libya" , "Feature of controversial election once" , "North central African country, capital N'Djamena" , "N central African country" .)