Go and reform a varlet (6)
I believe the answer is:
travel
'go' is the definition.
(I know that go can be written as travel)
'reform a varlet' is the wordplay.
'reform' indicates an anagram (letters in a new form).
'varlet' anagrammed gives 'TRAVEL'.
'and' acts as a link.
(Other definitions for travel that I've seen before include "Journey from one place to another" , "Varlet (anag.)" , "Voyage" , "Make a journey" , "Movement from one place to another" .)