Running arms -- tradition for runner? (13)
I believe the answer is:
administrator
'runner?' is the definition.
(someone who runs things)
'running arms tradition' is the wordplay.
'running' indicates an anagram (the letters run around to different places).
'arms'+'tradition'='armstradition'
'armstradition' is an anagram of 'ADMINISTRATOR'.
'for' acts as a link.
(Other definitions for administrator that I've seen before include "I'll manage" , "Official organiser" , "Business organiser" , "Executive" , "One who manages or directs" .)