Go off and act (4)
I believe the answer is:
turn
This clue is a double definition.
'go off' is the first definition.
(thesaurus)
'act' is the second definition.
(theatre)
'and' acts as a link.
(Other definitions for turn that I've seen before include "Rotate for a performer's act" , "Go - go round in circles - go off" , "Change direction" , "Go off - act" , "Transform - revolution" .)