Suppress, to remain on good terms with (4,2)
I believe the answer is:
keep in
'suppress' is the definition.
(thesaurus)
'remain on good terms with' is the wordplay.
I cannot quite understand how this works, but
'remain' could be 'keep' (keeping is a kind of remaining) and 'keep' is present in the answer.
The remaining letters 'in' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
'to' is the link.
Can you help me to learn more?
(Other definitions for keep in that I've seen before include "Conceal" , "Restrain" , "Contain" , "punish a pupil" , "Bottle up - shut up" .)