Trail thus coming north arriving at African city (5)
I believe the answer is:
lagos
'african city' is the definition.
(Nigerian city)
'trail thus coming north' is the wordplay.
'trail' becomes 'lag' (both can mean to go behind).
'thus' becomes 'so' ('so' can be a synonym of 'thus').
'coming north' says the letters should be written in reverse.
'so' back-to-front is 'os'.
'lag'+'os'='LAGOS'
'arriving at' is the link.
(Other definitions for lagos that I've seen before include "African port" , "Formerly capital of Nigeria" , "African city" , "Former Nigerian capital" , "Chief port and former capital of Nigeria" .)