Neighbor of Senegal (6)
(Other definitions for gambia that I've seen before include "Aim bag toward African state" , "West African river" , "West African country surrounded by Senegal" , "West African country, capital Banjul" .)
'neighbor of senegal' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mali that I've seen before include "Land" , "African state's" , "Send mail out to Africa" , "African country, once French Sudan" , "West African country, capital Bamako" .)