About to go and come back (6)
I believe the answer is:
return
'come back' is the definition.
('return' can be a synonym of 'come back')
'about to go' is the wordplay.
'about' becomes 're' (regarding).
'to go' becomes 'turn' (turning is a kind of going**).
're'+'turn'='RETURN'
'and' acts as a link.
(Other definitions for return that I've seen before include "reply" , "Profit earned on money" , "election to parliament" , "second half of journey" , "Give or come back" .)