River through Kazakhstan (4)
I believe the answer is:
ural
'river through kazakhstan' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ural that I've seen before include "The .... Mountains divide Europe and Asia" , "River feeding Caspian Sea" , "2,400 km river flowing through Russia and Kazakhstan into the Caspian Sea" , "Asian flower" , "The - mountains separate Asia and Europe" .)