River having nothing to East (4)
I believe the answer is:
nile
'river' is the definition.
(Nile River is an example)
'nothing to east' is the wordplay.
'nothing' becomes 'nil' ('nil' can be a synonym of 'nothing').
'to east' becomes 'e' ('E' can be a synonym of 'east').
'nil'+'e'='NILE'
'having' is the link.
(Other definitions for nile that I've seen before include "River of Egypt" , "River that's Blue and White" , "Egyptian river" , "white flower?" , "Green" .)