River of Africa, Northern Ireland and part of Germany? (5)
I believe the answer is:
'river of africa' is the definition.
(I've seen this in another clue)
'northern ireland and part of germany?' is the wordplay.
'northern ireland' becomes 'NI' (abbreviation).
'and' means one lot of letters go next to another.
'part of germany?' becomes 'ger' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
Can you help me to learn more?
(Other definitions for niger that I've seen before include "West African republic" , "Country in interior of N Africa, capital Niarney" , "River of West Africa" , "one flowing through Mali" , "West African river and country" .)