The way a wild mare can run (6)
I believe the answer is:
stream
'run' is the definition.
(streaming is a kind of running)
'the way a wild mare' is the wordplay.
'the way' becomes 'st'.
'a wild' is an anagram indicator.
'mare' is an anagram of 'ream'.
'st'+'ream'='STREAM'
'can' is the link.
(Other definitions for stream that I've seen before include "Transmit music or video online" , "Flow from master" , "Master (anag) - current" , "Fly" , "flower" .)