Make progress - not, for example, slipping back (3,2)
I believe the answer is:
get on
'make progress' is the definition.
(synonyms)
'not for example slipping back' is the wordplay.
I cannot really understand how this works, but
an anagram of 'not' is 'ton' which is present in the answer.
The remaining letters 'ge' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for get on that I've seen before include "Board (a bus)" , "Make progress or mount up" , "Obtain promotion" , "What boarders do" , "Make progress; be friends" .)