Obote's deposer (1,3)
'obote's deposer' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for amin that I've seen before include "'Idi ..., former Ugandan ruler (4)'" , "Dictator Idi --" , "Idi . . . . Once ruled Uganda tyrannically" , "Ugandan dictator" , "Brutal dictator" .)