Redraw line... line going generally northward in map of Africa (4)
I believe the answer is:
nile
'redraw line line going generally' is the definition.
I can't tell whether this defines the answer.
'northward in map of africa' is the wordplay.
'northward' says the letters should be written backwards (in down clue going up).
'map of africa' becomes 'le' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' reversed gives 'ni'.
'ni'+'le'='NILE'
Can you help me to learn more?
(Other definitions for nile that I've seen before include "Egypt's river" , "River (which is originally blue and white)" , "World's longest river" , "African river" , "Current" .)