Runner turned green after hash (9)
I believe the answer is:
messenger
'runner' is the definition.
(I've seen this before)
'turned green after hash' is the wordplay.
'turned' is an anagram indicator.
'after' means one lot of letters go next to another.
'hash' becomes 'mess' (making a hash of something is making a mess of it).
'green' is an anagram of 'enger'.
'enger' after 'mess' is 'MESSENGER'.
(Other definitions for messenger that I've seen before include "He takes note" , "Courier - don't shoot him" , "Person carrying information to another" , "Bringer of news, etc" , "Emissary, courier" .)