Go or come after (6)
I believe the answer is:
follow
This clue is a double definition.
'go' is the first definition.
(following is a kind of going)
'come after' is the second definition.
(synonyms)
(Other definitions for follow that I've seen before include "Go or come after" , "Pursue or understand" , "Chase" , "'____ and don't dilly-dally on the way'" , "Ensue" .)