Runner miles north of German city, for example, going over river (9)
I believe the answer is:
messenger
'runner' is the definition.
(I've seen this before)
'north of german city for example going over river' is the wordplay.
'north of' becomes 'm' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'german city' becomes 'essen' (city in Germany).
'for example' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'going over' shows that the letters should be reversed in order.
'river' becomes 'r' (abbreviation for river).
'eg' in reverse letter order is 'ge'.
'm'+'essen'+'ge'+'r'='MESSENGER'
'miles' acts as a link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for messenger that I've seen before include "Delivery boy" , "He takes note" , "Runner" , "Communication carrier" , "He's just bringing the word - don't shoot him" .)