Put in for rerun, sore and inept (9)
I believe the answer is:
interpose
'put in' is the definition.
(synonyms)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for interpose that I've seen before include "Place between" , "Muscle in" , "Insert between (one thing and another)" , "mediate" , "step in" .)