Chooses to stop running (4)
I believe the answer is:
opts
'chooses' is the definition.
(I've seen this before)
'stop running' is the wordplay.
'running' indicates an anagram (the letters run around to different places).
'stop' anagrammed gives 'OPTS'.
'to' acts as a link.
(Other definitions for opts that I've seen before include "Selects between alternatives" , "Selects as an alternative" , "Settles" , "Makes a choice from a range" , "Chooses from a range of possibilities" .)