Nothing in old money for European runner (5)
I believe the answer is:
loire
'european runner' is the definition.
(runner being something that runs - a river)
'nothing in old money' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'in' is an insertion indicator.
'old money' becomes 'lire' (Italian currency 1861-2002).
'o' put within 'lire' is 'LOIRE'.
'for' acts as a link.
(Other definitions for loire that I've seen before include "Wine region" , "flower found amid vineyards" , "Longest river in France" , "part of France" , "Longest French river" .)