Right exit to turn back? (7)
I believe the answer is:
regress
'to turn back?' is the definition.
('regress' can be a synonym of 'turn back')
'right exit' is the wordplay.
'right' becomes 'r' (common abbreviation).
'exit' becomes 'egress' (I've seen this in another clue).
'r'+'egress'='REGRESS'
(Other definitions for regress that I've seen before include "Return to former life" , "Go back to earlier state, perhaps of health" , "Go back to more primitive state" , "Revert, throw back" , "Go backwards, disimprove" .)