Close in on border south of central Accra (8)
I believe the answer is:
converge
'close in' is the definition.
(thesaurus)
'on border south of central accra' is the wordplay.
'border' becomes 'verge' (verge is a kind of border**).
'south of' says to put letters next to each other.
'central' indicates the central letters.
The middle letter of 'accra' is 'c'.
'on'+'verge'='onverge'
'onverge' put after 'c' is 'CONVERGE'.
(Other definitions for converge that I've seen before include "Tend to meet at a point" , "Move towards meeting" , "Come towards the same point like Congreve" , "Come together" , "fuse" .)