Go back, darlings! (4)
I believe the answer is:
step
'go' is the definition.
(stepping is a kind of going)
'back darlings' is the wordplay.
'back' is a reversal indicator.
'darlings' becomes 'pets' ('pet' can be a synonym of 'darling').
'pets' written backwards gives 'STEP'.
(Other definitions for step that I've seen before include "Dance move" , "Abrupt change; pace" , "Footfall" , "some progress" , "Pace; foothold" .)