US cities caging American antelope (5)
I believe the answer is:
nyala
'antelope' is the definition.
(nyala is a kind of antelope)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for nyala that I've seen before include "South African resident" , "Ruminant" , "one of a herd" , "Spiral-horned antelope" , "beast" .)