Foreign money flowed into football club (5)
I believe the answer is:
franc
'foreign money' is the definition.
(eg Swiss franc)
'flowed into football club' is the wordplay.
'flowed' becomes 'ran' ('run' can be a synonym of 'flow').
'into' is an insertion indicator.
'football club' becomes 'fc'.
'ran' placed into 'fc' is 'FRANC'.
(Other definitions for franc that I've seen before include "Swiss currency unit" , "European currency until the end of 2001" , "Foreign currency" , "Former French coin" , "One hundred centimes in Benin" .)