River in east with hot flowing water? (5)
I believe the answer is:
rhine
'water?' is the definition.
(I know that Rhine is a river)
'river in east with hot flowing' is the wordplay.
'river' becomes 'r' (abbreviation for river).
'east' becomes 'e' (abbreviation).
'with' means one lot of letters go next to another.
'hot' becomes 'h' (common abbreviation eg on taps).
'flowing' indicates anagramming the letters.
'in'+'e'+'h'='ineh'
'ineh' anagrammed gives 'hine'.
'r'+'hine'='RHINE'
(Other definitions for rhine that I've seen before include "valley" , "Cologne's river" , "water" , "Great river in Germany with Lorelei Rock" , "Ring river (Wagner)" .)