Do work in part of Africa (5)
I believe the answer is:
congo
'part of africa' is the definition.
('Congo' is part of 'africa')
'do work' is the wordplay.
'do' becomes 'con'.
'work' becomes 'go' (synonyms).
'con'+'go'='CONGO'
'in' is the link.
(Other definitions for congo that I've seen before include "Crazily entertaining" , "African river flowing into the South Atlantic" , "African river also called Zaire" , "Central African region" , "Former name of Zaire" .)